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2012 International Workshop
on EUV and Soft X-Ray Sources
October 8-11, 2012 Dublin ▪ Ireland
Workshop Abstracts
2012 International Workshop on EUV and Soft X-Ray Sources
www.euvlitho.com 1
2012 International Workshop on EUV and Soft X-ray Sources is organized by:
Please visit www.euvlitho.com for additional information.
2012 International Workshop on EUV and Soft X-Ray Sources
www.euvlitho.com 2
2012 International Workshop on EUV and Soft X-ray Sources
Workshop Sponsors
Workshop Co-Organizers
2012 International Workshop on EUV and Soft X-Ray Sources
www.euvlitho.com 3
Welcome
Dear Colleagues;
I will like to welcome you to the 2012 International Workshop on EUV and Soft X-Ray
Sources in Dublin, Ireland.
3rd annual source workshop is now the largest annual gathering of EUV and XUV source experts. This workshop will provide a forum for researchers in the EUV and soft X-ray areas to present their work and
discuss potential applications of their technology. I expect that researchers as well as the end-users of EUV and soft X-ray sources will
find this workshop valuable. The workshop proceedings will be published online.
The EUV Source Workshop is organized by University College Dublin (UCD) and EUV Litho, Inc. This workshop has been made possible by
the support of workshop sponsors, technical working group (TWG), workshop support staff, session chairs and presenters. I would like to thank them for their contributions and making this workshop a success. I look forward to your participation in the workshop.
Best Regards
Vivek Bakshi
Organizing Chair, 2012 International Workshop on EUV and Soft X-Ray Sources
2012 International Workshop on EUV and Soft X-Ray Sources
www.euvlitho.com 4
Source Technical Working Group (TWG) Reza Abhari (ETH Zurich) Jinho Ahn (Hanyang University) Peter Anastasi (Silson) Sasa Bajt (DESY) Vadim Banine (ASML) Klaus Bergmann (XTREME / ILT-Fraunhofer) Davide Bleiner (University of Bern)
Vladimir Borisov (Triniti) John Costello (DCU) Samir Ellwi (Adlyte) Akira Endo (Waseda University) Henryk Fiedorowicz (Military University of Technology, Poland) Torsten Feigl (IOF-Fraunhofer)
Francesco Flora (ENEA) Debbie Gustafson (Energetiq) Ahmed Hassanein (Purdue) Takeshi Higashiguchi (Utsunomia University) Larissa Juschkin (Aachen University) Hiroo Kinoshita (Hyogo University) Chiew-seng Koay (IBM)
Konstantin Koshelev (ISAN) Rainer Lebert (Bruker) Peter Loosen (ILT-Fraunhofer) Eric Louis (FOM) James Lunney (Trinity College, Dublin) John Madey (University of Hawaii) Shunko Magoshi (EIDEC)
Alan Michette (King's College London)
Hakaru Mizoguchi (Gigaphoton) Katsuhiko Murakami (Nikon) Patrick Naulleau (LBNL) Katsunobu Nishihara (Osaka University) Fergal O'Reilly (UCD)
Gerry O'Sullivan (UCD) Luca Ottaviano (University of L'Aquila) Yuriy Platonov (RIT) Martin Richardson (UCF) Valentino Rigato (INFN-LNL) Jorge Rocca (University of Colorado) David Ruzic (University of Illinois)
Akira Sasaki (JAEA) Leonid Shmaenok (PhysTex) Menachem Shoval (Intel) Emma Sokell (UCD)
Harun Solak (PSI) Seichi Tagawa (Osaka University) Mark Tillack (UC San Diego)
Andrei Yakunin (ASML) Hironari Yamada (PPL) Sergey Zakharov (EPPRA) Vivek Bakshi (EUV Litho, Inc.) - Organizing Chair Padraig Dunne (UCD) - Organizing Co-Chair
2012 International Workshop on EUV and Soft X-Ray Sources
www.euvlitho.com 5
Workshop Agenda
2012 International Workshop on EUV and Soft X-Ray Sources
www.euvlitho.com 6
Agenda Outline
Monday, October 8, 2012
Location: Newman House, Stephen’s Green, Dublin
6:00 - 7:00 PM Reception and Speaker Prep
Tuesday, October 9, 2012
Location: Clinton Auditorium,
UCD Campus, Dublin 7:45 AM Pickup at the Hotel (Stephen’s Green and
Burlington Hotel) 8:30 AM – 11:30 AM Workshop Presentations
11:40 AM -12:40 PM Lunch 12:40 PM – 5:30 PM Workshop Presentations 5:30 PM – 6:30 PM Poster Session and Reception 6:30 PM Depart for Off-Site Dinner (Pickup at Clinton
Auditorium)
2012 International Workshop on EUV and Soft X-Ray Sources
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Wednesday, October 10, 2012
Location: Clinton Auditorium UCD Campus, Dublin
7:45 AM Pickup at the Hotel (Stephen’s Green and
Burlington) 8:30 AM – 1:00 PM Workshop Presentations
1:00 PM - 2:00 PM Lunch 2:00 PM Depart for tour of Trim Castle
(Pickup at Clinton Auditorium)
Thursday, October 11, 2012
Location: Newman House, Stephen’s Green, Dublin
Technical Working Group (TWG) Meeting 8:30 AM Continental Breakfast 9:00 AM – 10:00 AM TWG Meeting
2012 International Workshop on EUV and Soft X-Ray Sources
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WORKSHOP AGENDA
2012 International Workshop on EUV and
Soft X-Ray Sources
October 8-11, 2012, Dublin, Ireland
Monday, October 8, 2012 (Newman House)
6:00 PM – 7:00 PM Reception and Registration
Tuesday, October 9, 2012 (Clinton Auditorium)
8:30 AM Session 1 : Welcome and Announcements
Introduction and Announcements (Intro-1) Vivek Bakshi, EUV Litho, Inc., USA
Des Fitzgerald, VP, UCD
8:40 AM Session 2: Keynote-1
Session Chair: Vadim Banine (ASML)
High Repetition Rate Table-top Soft X-Ray Lasers (S1) J. J. Rocca1,2,3, B. Reagan 1,2, Y. Wang,1,2 , D. Alessi, B. M. Luther1,2,
K. Wernsing1,2, L. Yin 1,2 , M. A. Curtis 1,2, M. Berrill1,2 , D. Martz 1,2 ,
V.N. Shlyaptsev1,2 , S. Wang 1,2 , F. Furch 1,3, M. Woolston 1,2, D. Patel 1,2,
C.S. Menoni 1,2 1 National Science Foundation ERC for Extreme Ultraviolet Science and Technology 2 Electrical and Computer Engineering Department, Colorado State University, Fort Collins, CO 80523 3 Physics Department, Colorado State University, Fort Collins, CO 80523
Extendibility of LPP EUV Source Technology in Higher Power (kW) and Shorter Wavelength (6.x nm) Operation (S2)
Akira Endo Waseda University, Tokyo, Japan
HiLASE Project, Prague, Czech Republic
2012 International Workshop on EUV and Soft X-Ray Sources
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Awards and Announcements – Padraig Dunne (UCD) Break 10:00 AM 10:20 AM Session 3: HVM EUV Sources Session Chair: Katsuhiko Murakami (NIKON)
EUV Lithography: Today and Tomorrow? (S10) (Invited Paper) Vadim Banine
ASML, The Netherlands
EUVL - A Reality in the Making The Reality of Laser Assisted Discharge Plasma EUV Light Sources (S49)
(Invited Paper) Jeroen Jonkers
XTREME technologies, GmbH, Steinbachstrasse 15, 52074 Aachen, Germany
New type of DPP source with liquid tin jets electrode - recent progress (S61)
V.Krivtsun *, O.Yakushev *, A.Vinohodov*, ** , V.Borisov** , V.Ivanov* and K.Koshelev*.
* RnD-ISAN / EUVLabs, ** TRINITI
High Brightness, High-average Power Picosecond Thin Disc Laser Program to Specific Requirements from Short Wavelength Light Sources (S28)
Taisuke Miura, Michal Chyla, Martin Smrž, Patricie Severová, Ondřej Novák,
Akira Endo, and Tomáš Mocek HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 182 21 Prague 8, Czech
Republic
Lunch 11:40 AM
12:40 PM Session 4: EUV Sources for Mask Metrology
Session Co-Chairs: Klaus Bergman (ILT-Fraunhofer) and Larissa Juschkin (RWTH – Aachen)
EUV Source For Metrology of EUV Masks (Tentative title) (S51) (Invited Paper)
Heiko Feldmann Carl Zeiss, 73447 Oberkochen, Germany
Discharge based EUV Source for Metrology (S58) (Invited Paper)
2012 International Workshop on EUV and Soft X-Ray Sources
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Klaus Bergmann Fraunhofer Institute for Laser Technology, Steinbachstr. Aachen, Germany
Electrodeless Z-PinchTM EUV Source for Next Generation EUV Metrology (S36) (Invited Paper)
Deborah Gustafson, Stephen F. Horne, Matthew M. Besen, Donald K. Smith, Matthew J. Partlow, Paul A. Blackborow Energetiq Technology, Inc., 7 Constitution Way, Woburn, MA, USA 01801
Recent Progress on High Brightness Source Collector Module for EUV Mask
Metrology (S31) Paul Sheridan1, Kenneth Fahy1, Padraig Dunne2, and Fergal O’Reilly2
1NewLambda Technologies Ltd, Science Center North, Belfield, Dublin 4, Ireland 2 UCD School of Physics, UCD, Stillorgan Rd, Dublin 4, Ireland
Source Brightness Requirements for EUV Microscopes (S39)
(Invited Paper) Larissa Juschkin1, Fergal O’Reilly2 1RWTH Aachen University, Experimental Physics of EUV, Steinbachstr. 15, 52074 Aachen, Germany
and JARA - Fundamentals of Future Information Technology (FIT), 52425 Jülich, Germany 2School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
Break 2:00 PM (20 Minutes)
2:20 PM Session 5: Modeling Session Co-Chairs: Gerry O’Sullivan (UCD) and Sergey Sergey V. Zakharov (EPPRA)
Modeling and Optimization of Pre-conditioned LPP targets (S52) (Invited Paper) K. N. Koshelev1,2, V. V. Ivanov1,2, V. G. Novikov1,3, V. M. Krivtsun1,2, A. S. Grushin1,3 , V.
Medvedev4 1RnD-ISAN, Troitsk, 142090 Russia 2Institute of Spectroscopy RAS, Troitsk, 142090 Russia 3Keldysh Institute of Applied Mathematics RAS, Moscow, 125047 Russia 4Dutch Institute for Fundamental Energy Research, Nieuwegein, The Netherlands
Unresolved Transition Arrays and their role in EUV and Soft X-ray Source Development (S56)
2012 International Workshop on EUV and Soft X-Ray Sources
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Gerry O’Sullivan1, John Costello2, Thomas Cummins1, Rebekah D’Arcy1, Padraig Dunne1, Akira Endo3, Paddy Hayden2, Takeshi Higashiguchi4, Imam Kambali1, Deirdre Kilbane1, Bowen Li1, Colm O’Gorman1, Takamitsu Otsuka4, Emma Sokell1 and Noboru Yugami4 1School of Physics, University College Dublin, Belfield, Dublin 4, Ireland. 2School of Physics, Dublin City University, Glasnevin, Dublin 9 3HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 18221 Prague 8, Czech Republic 4Department of Advanced Interdisciplinary Sciences, Utsunomiya University, Yoto 7-1-2,
Utsunomiya, Tochigi 321-8585 Japan.
Properties of High-intensity EUV & Soft-X Radiation Plasma Sources (S25) (Invited Paper) Vasily S. Zakharov1,2, Sergey V. Zakharov 1,2,3, Peter Choi1 1EPPRA sas, Villebon sur Yvette, France in collaboration with KIAM RAS, Moscow, Russia 2NRC Kurchatov Institute, Moscow, Russia 3JIHT RAS and SRC RF TRINITI, Moscow, Russia
4:00 PM Session 6: EUV/ BEUV/ XUV Optics
Session Co-Chairs: Eric Louis (DIFFER) and Yuriy Platonov (RIT)
Multilayers for 6.8 nm Wavelength (S50) (Invited Paper) I.A. Makhotkin1, E. Louis1 ,E. Zoethout1, R.W.E. van de Kruijs1, Andrei M. Yakunin2, Stephan
Müllender3 and F. Bijkerk1,4 1 FOM Institute DIFFER - Dutch Institute for Fundamental Energy Research, Nieuwegein,
the Netherlands 2 ASML, Veldhoven, the Netherlands 3 Carl Zeiss SMT GmbH, Oberkochen, Germany 4 MESA+ Institute for Nanotechnology, University of Twente, Enschede, the Netherlands
New High Reflective Multilayer Designs for the EUV and Soft X-ray Range (S57) (Invited paper) Marco Perske, Hagen Pauer, Tobias Fiedler, Sergiy Yulin, Viatcheslav Nesterenko, Mark
Schürmann, Torsten Feigl, Norbert Kaiser Fraunhofer-Institut für Angewandte Optik und Feinmechanik, Albert-Einstein-Str.
7, 07745 Jena, Germany
Optics for EUV/XUV/XR Sources and Laboratory Submicron Microscopy (S55) (Invited Paper)
Ladislav Pina1, Veronika Pickova1, Radka Havlikova1, Hana Zakova2, Alexandr Jancarek1,
Adolf Inneman3, Martin Horvath3, Jiri Marsik3, Peter Oberta3, Henryk Fiedorowicz4, Andrzej
Bartnik4 1 Czech Technical University in Prague, Faculty of Nuclear Sciences and Phys. Engineering, 115 19 Prague 1, Czech Republic
2012 International Workshop on EUV and Soft X-Ray Sources
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2Czech Technical University in Prague, Faculty of Biomedical Engineering, 272 01 Kladno, Czech Republic 3Rigaku Innovative Technologies Europe, 142 21 Prague 4, Czech Republic 4Military University of Technology, Institute of Optoelectronics, 00-908 Warszawa 49, Poland
Corrosion-resistant, Triple-wavelength Mg/SiC Multilayer Coatings for the 25-80 nm Wavelength Region (S45) (Invited Paper)
Regina Soufli1, Mónica Fernández-Perea1, Jeff C. Robinson1, Sherry L. Baker1, Jennifer Alameda1, Christopher C. Walton1, Luis Rodríguez-De Marcos2, Jose A. Méndez2, Juan I.
Larruquert2, Eric M. Gullikson3 1Lawrence Livermore National Laboratory, Livermore, California, US 2Instituto de Óptica, Consejo Superior de Investigaciones Científicas, Madrid, Spain 3Lawrence Berkeley National Laboratory, Berkeley, California, US
Nanoscale Multilayer Membranes as Optical Elements for EUVL (S59) Nikolay Chkhalo1, Mikhail Drozdov1, Evgeny Kluenkov1, Aleksei Lopatin1, Valerii Luchin1, Nikolay Salashchenko1, Nikolay Tsybin1, Leonid Sjmaenok2 ,Vadim Banine3, Luigi
Scaccabarozzi3, Andrei Yakunin3 1Institute for Physics of Microstructures RAS,Ulyanova 46, 603155 Nizhniy, Novgorod,
Russia 2PhysTeX, Jos Francotteweg 6b, 6291 GP Vaals, Netherlands 3ASML Netherlands, De Run 6501, 5504 DR Veldhoven, Netherlands
5:30 PM – 6:30 PM Session 7: Poster Session
7:00 PM Depart for Off-site Dinner (Royal Dublin Society)
End of Day 2
2012 International Workshop on EUV and Soft X-Ray Sources
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5:30 PM Session 7: Poster Session
Topic: HVM Sources Next Generation of EUV Lithography: Challenges and Opportunities (S47)
Andrei M. Yakunin, Vadim Banine ASML, Veldhoven, The Netherlands
Direct Diagnostics Concept for High Power CO2 Laser at the LPP Focus Spot (S20) Kazuyuki Sakaue, Yasufumi Yoshida, Ryo Sato, Masakazu Washio, Akira Endo
Research Institute for Science and Engineering, Waseda university, 3-4-1 Okubo, Shinjuku, Tokyo 169-855 Japan
Research of the CO2 Laser MOPA System (S44) Wang Xinbing1*, Zuo DuLuo1, Lu Peixiang2
1Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China 2 School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
2D PIC Modeling of the EUV Induced Hydrogen Plasma and Comparison to the Observed Carbon Etching Rate (S27) D.I. Astakhov1,3*, W.J. Goedheer1, D.V. Lopaev2, V.V. Ivanov3, V.M. Krivtsun3,
O. Yakushev3, K.N. Koshelev3, and F. Bijkerk1,4 1 FOM Institute DIFFER - Dutch Institute for Fundamental Energy Research, P.O. Box 1207,
3430 BE Nieuwegein, The Netherlands
2 Institute of Nuclear Physics, Moscow State University, Russia
3 Institute for Spectroscopy, Russian Academy of Sciences, Troitsk, Russia
4 MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
Topic: EUV Sources for Mask Metrology Feasibility Study of Microplasma High-brightness EUV Source at 13.5 nm (S13)
Takeshi Higashiguchi1, Yoichi Hirose1, Yuhei Suzuki1, Takamitsu Otsuka1, Jun-ichiro Sugisaka1, Akira Endo2, Padraig Dunne3, and Gerry O'Sullivan3 1Department of Advanced Interdisciplinary Sciences, Center for Optical Research &
Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan 2HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 18221 Prague 8, Czech Republic 3School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
Diagnostics and Modeling of Gas Puff Target Laser Plasma Radiation Source (S18)
Sarka Vondrova1, Dalibor Panek1, Petr Bruza1, Miroslava Vrbova1, Pavel Vrba2, Przemyslaw Wachulak3,Frantisek Krejci1, 4, Jan Jakůbek4 1Czech Technical University in Prague, Faculty of Biomedical Engineering, 272 01 Kladno,
Czech Republic
2012 International Workshop on EUV and Soft X-Ray Sources
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2 Institute of Plasma Physics, Academy of Sciences, 182 00 Prague 8, Czech Republic 3Military University of Technology, Institute of Optoelectronics, 00-908 Warszawa 49, Poland 4 Czech Technical University in Prague, Institute of Experimental and Applied Physics, 128 00 Prague 2, Czech Republic
In-situ Diagnostics for Plasma based Extreme Ultraviolet Sources (S22) T. W. Versloot, F.T. Molkenboer, H.H.P.Th. Bekman, N.B. Koster, E. te Sligte, R. Verberk,
R.C.M. Pohlmann, F.H. Elferink TNO Delft, Stieltjesweg 1, 2628 CK, Delft, the Netherlands
Laser-initiated Discharge-produced Plasma Ablated from Liquid Metal Electrodes (S26)
Vasily S. Zakharov1*
, Larissa Juschkin2
, Sergey V. Zakharov 1*+
, Gerry O’Sullivan3, Emma
Sokel3, Isaac Tobin4
1
EPPRA sas, Villebon sur Yvette, France in collaboration with KIAM RAS, Moscow, Russia 2
RWTH Experimental Physics, Aachen, Germany 3 University College Dublin, Ireland 4 Trinity College Dublin, Ireland * also with NRC Kurchatov Institute, Moscow, Russia +
also with JIHT RAS and SRC RF TRINITI, Moscow, Russia
EUV Emission from Laser-triggered Z-pinch Discharge (S30) Isaac Tobin1, Larissa Juschkin2,3, Fergal O’Reilly2,
Paul Sheridan4, Emma Sokel2, James G. Lunney1 1School of Physics, Trinity College Dublin, Dublin 2, Ireland. 2School of Physics, University College Dublin, Belfield, Dublin 4, Ireland. 3Department of Physics, RWTH Aachen University, Steinbachstr. 15 D-52074 Aachen, Germany. 4Newlambda Technologies, UCD Science Centre North, Belfield, Dublin 4, Ireland.
Topic: Applications of EUV Sources
R&D Actinic Blank Inspection Microscope (S40) Larissa Juschkin1, Stefan Herbert2, Aleksey Maryasov2, Serhiy Danylyuk2, Rainer Lebert3 1RWTH Aachen University, Experimental Physics of EUV, Steinbachstr. 15, 52074 Aachen, Germany 2RWTH Aachen University, Chair for Technology of Optical Systems, 52074 Aachen,
Germany
2012 International Workshop on EUV and Soft X-Ray Sources
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3Bruker Advanced Supercon GmbH, Waltherstrasse 49-51, 51069 Köln, German Exploring the Resolution Limit of the Talbot lithography with EUV Light (S41)
Hyun-su Kim1, Serhiy Danylyuk2, Sascha Brose2, Klaus Bergmann3, Detlev Grützmacher4, Larissa Juschkin1
1RWTH Aachen University, Experimental Physics of EUV, Steinbachstr. 15, 52074 Aachen, Germany 2RWTH Aachen University, Chair for Technology of Optical Systems, 52074 Aachen,
Germany 3Fraunhofer Institute for Laser Technology, Steinbachstr. 15, Aachen, Germany 4Peter Grünberg Institute 9 (PGI-9): Semiconductor Nanoelectronics, Research Center Jülich and JARA - Fundamentals of Future Information Technology (FIT), 52425 Jülich, Germany
Topic: Modeling
Modeling of Absorption and Scattering of IR laser Radiation by LPP Targets (S53)
A. S. Grushin1,2, I. P. Tsygvintsev1,2, V. G. Novikov1,2, V. V. Ivanov1,3 1RnD-ISAN, Troitsk, 142090 Russia 2Keldysh Institute of Applied Mathematics RAS, Moscow, 125047 Russia 3Institute for Spectroscopy RAS, Troitsk, 142090 Russia
Modeling of Plasma Dynamics and EUV Generation for Distributed Sn Targets Irradiated with Short Laser Pulses (S54)
V. Ivanov1, A. Grushin2, V. Novikov2, V. Medvedev3, V. Krivtsun1, A. Yakunin4, and K. Koshelev1 1Institute for Spectroscopy RAS, Troitsk, Russia 2Keldysh Institute of Applied Mathematics, Moscow, Russia 3Dutch Institute for Fundamental Energy Research, Nieuwegein, The Netherlands 4ASML, The Netherlands
Topic: BEUV
Alternative Future 6.x nm EUV Sources from Strong In-band Line Emission (S29)
Thomas Cummins1, Takamitsu Otsuka2, Tony Donnelly1, Weihua Jiang3, Akira Endo4, Padraig Dunne1, Gerry O’Sullivan1 and Takeshi Higashiguchi2 1School of Physics, University College Dublin, Belfield, Dublin 4, Ireland 2Department of Advanced Interdisciplinary Sciences, Center for Optical Research & Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya
University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan 3Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan 4 HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 182 21 Prague 8, Czech Republic
2012 International Workshop on EUV and Soft X-Ray Sources
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A Tunable Beyond Extreme Ultraviolet Source at 6.x nm based on a Laser-produced Plasma from a High-Z Target Mix (S32) Colm O’Gorman1, Takamitsu Otsuka2, Weihua Jiang3, Akira Endo4, Bowen Li1, Thomas
Cummins1, Padraig Dunne1, Emma Sokell1, Gerry O’Sullivan1, and Takeshi Higashiguchi2
1School of Physics, University College Dublin, Belfield, Dublin 4, Ireland 2Department of Advanced Interdisciplinary Sciences, Center for Optical Research & Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan 3Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan 4 HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 182 21 Prague 8, Czech Republic
Identification of Atomic Resonances for Enhancement of High Harmonic Generation in Laser-produced Plasmas (S35)
R. Stefanuika, N. Krstulovica, M. Mahmoadb, P. Dunnea, G. O’Sullivana
a:School of Physic, University college Dublin, Ireland
b: Institute Of Lasers for postgraduate studies, University of Baghdad, Iraq EUV Spectra of Highly Charged Heavy Ions in the NIST EBIT (S60)
D. Kilbanea, J. D. Gillaspyb, Yu. Ralchenkob, J. Readerb, G. O'Sullivana a School of Physics, University College Dublin, Belfield, Dublin 4, Ireland b National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Topic: XUV
Possibility of High-Z Plasma Water Window Sources (S14) Takeshi Higashiguchi1, Takamitsu Otsuka1, Weihua Jiang2, Akira Endo3, Bowen Li4, Deirdre Kilbane4, Padraig Dunne4, and Gerry O'Sullivan4 1Department of Advanced Interdisciplinary Sciences, Center for Optical Research & Education (CORE), and Optical Technology Innovation Center (OpTIC),
Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan 2Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan 3HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 18221 Prague 8, Czech Republic 4School of Physics, University College Dublin, Belfield, Dublin 4, Ireland A Capillary Discharge-preformed Argon Plasma Waveguide for a Coherent Soft X-
ray Source (S15) Shohei Sakai1, Takeshi Higashiguchi1, Nadezhda Bobrova2, Pavel Sasorov2, and Noboru
Yugami1
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1Department of Advanced Interdisciplinary Sciences, Center for Optical Research & Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan 2Institude for Theoretical and Experimental Physics, B. Cheremushkinskaya str. 25, 117218 Moscow, Russia
Measurement of Spectra in Water- window Wavelength Region (S23) J. Novak1, M. Nevrkla1, A. Jancarek1, M. Vrbova2, P. Vrba3 1Czech Technical University, Faculty of Nuclear Sciences and Physical Engineering, 115 19 Prague 1, Czech Republic 2Czech Technical University, Faculty of Biomedical Engineering, 272 01 Kladno, Czech Republic 3Institute of Plasma Physics, Academy of Sciences, 182 00 Prague 8, Czech Republic
Characterization of Capillary Discharge Water-Window Radiation Source (S24)
Michal Nevrkla1, Jan Novak1, Alexandr Jancarek1, Pavel Vrba2, Miroslava Vrbova3 1 Czech Technical University in Prague, Faculty of Nuclear Sciences and Phys. Engineering, 115 19 Prague 1, Czech Republic 2 Institute of Plasma Physics, Academy of Sciences, 182 00 Prague 8, Czech Republic 3Czech Technical University in Prague, Faculty of Biomedical Engineering, 272 01 Kladno,
Czech Republic
Emission Properties of Non-equilibrium Zirconium Plasma in Soft X-ray Region (S33)
Vasily S. Zakharov*, Sergey V. Zakharov *+ EPPRA sas, Villebon sur Yvette, France
in collaboration with KIAM RAS, Moscow, Russia * also with NRC Kurchatov Institute, Moscow, Russia + also with JIHT RAS and SRC RF TRINITI, Moscow, Russia
A Commercial Laboratory Soft-X-ray Source for Water Window Microscopy (S37)
Stephen F. Horne, Matthew M. Besen, Donald. K Smith Energetiq Technology, Inc., 7 Constitution Way, Woburn, MA, USA 01801
Spectral Characterization of XUV Sources based on Plasmas Induced by Laser and Capillary Discharge (S38)
P. Kolar1, D. Panek1, M. Vrbova1, M. Nevrkla2, P. Vrba3, and A. Jancarek 2
1Czech Technical University in Prague, Faculty of Biomedical Engineering, Nam. Sitna 3105,
272 01 Kladno, Czech Republic 2Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Trojanova 13, 120 00 Praha 2, Czech Republic 3Institute of Plasma Physics, The Academy of Sciences of the Czech Republic, Za Slovankou 1782/3, 182 00 Prague, Czech Republic
2012 International Workshop on EUV and Soft X-Ray Sources
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XUV Spectroscopy of the Interaction of Laser-produced Plasma with Solid Surfaces (S42)
A S Kuznetsov1, R Stuik2, F Bijkerk1,3, Eric Louis and A P Shevelko4. 1 FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Postbus 1207, 3430 BE Nieuwegein, The Netherlands (www.differ.nl) 2 Leiden Observatory, Universiteit Leiden, Postbus 9513,2300 RA Leiden, The Netherlands 3 MESA+ Institute for Nanotechnology, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands 4 P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 117924 Moscow, Russia
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Wednesday, October 10, 2012
8:30 AM Announcements
Introduction and Announcements (Intro-2)
Vivek Bakshi, EUV Litho, Inc.
Poster Session Awards and Announcements Padraig Dunne (UCD)
8:40 AM Session 9: Keynote-2
Session Chair: Padraig Dunne (UCD)
Microfocus Sources for EUV and X-ray Applications (S3) Alan Michette Department of Physics, King's College London, Strand, London WC2R 2LS, UK
9:35 AM Session 10: Business Presentations Session Chair: Padraig Dunne (UCD)
Erasmus Mundus Joint Doctorate Programme EXTATIC (EUV and X-Ray Training in
Advanced Technologies for Interdisciplinary Cooperation) - Program Review (S48)
Paul van Kampen
School of Physical Sciences, Dublin City University, Dublin, Ireland
10:05 AM Break (20 Minutes)
2012 International Workshop on EUV and Soft X-Ray Sources
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10:20 AM Session 11: BEUV
Session Co-Chairs: Udo Dinger (Carl Zeiss) and Takeshi Higashiguchi (Utsunomia University)
Plasma-based UTA Emission in BEUV & Water Window Spectral Regions
(S11) (Invited Paper) Takeshi Higashiguchi1, Takamitsu Otsuka1, Weihua Jiang2, Akira Endo3, Thomas
Cummins4, Colm O’Gorman4, Bowen Li4, Deirdre Kilbane4, Padraig Dunne4, and Gerry O'Sullivan4 1Department of Advanced Interdisciplinary Sciences, Center for Optical Research & Education (CORE), and Optical Technology Innovation Center (OpTIC),
Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan 2Department of Electrical Engineering, Nagaoka University of Technology, Kami-
tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan 3HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 18221 Prague 8, Czech Republic 4School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
Dual Laser Plasma Photoabsorption Studies Of Gadolinium In The Extreme
Ultraviolet Region (S34) (Invited Paper) Paddy Hayden, C. Fallon, T. J. Kelly and J. T. Costello School of Physical Sciences/National Centre for Plasma Science and Technology, Dublin City
University, Glasnevin, Dublin 9, Ireland
Highlights from a Recent BEUV Source Workshop (September 26, 2012, Japan) (S12)
Takeshi Higashiguchi Utsunomiya University
Concept Study on an Accelerator based Source for 6.x nm Lithography (S16)
Udo Dinger1, Diana Tuerke1, Atoosa Meseck2, Michael Patra1, Erik Sohmen1, Andreas Jankowiak2 1 Carl Zeiss SMT GmbH, Rudolf – Eber - Straße 2, 73447 Oberkochen 2 Helmholtz-Zentrum Berlin für Materialien und Energie GmbH,
Hahn-Meitner-Platz 1, 14109 Berlin
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Session 12: XUV and Applications
Session Co-Chairs: Ladislav Pina (RIT-Europe) and Rainer Lebert (Bruker)
High-brightness Liquid-jet Laser-plasma Enabling 10-second-exposure Water-window Cryo Microscopy (S43) (Invited Paper)
M. Selin1, D. H. Martz1, O. von Hofsten1, E. Fogelquist1, A. Holmberg1, U. Vogt1, H. Legall2, G. Blobel2, C. Seim3, H.Stiel2, and H. M. Hertz1
1Biomedical and X-Ray Physics, Dept. of Applied Physics, KTH Royal Inst. of Technology/Albanova, 10691 Stockholm, Sweden 2Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany 3Institute of Optics and Atomic Physics - Analytical X-ray physics, Technische
Universität Berlin, 10623 Berlin, Germany Whole Cell Cryogenic Soft X-ray Tomography with a Laboratory Light Source (S21) (Invited Paper)
D.B. Carlson1, J. Gelb2, V. Palshin2 and J.E. Evans1,3,* 1Dept. of Molecular and Cellular Biology, University of California at Davis, Davis, CA,
USA 2Xradia, Inc., Pleasanton, CA, USA 3Pacific Northwest National Lab, Environmental Molecular Sciences Lab, Richland, WA, USA
Capillary Plasma Radiation Source in the Soft X-Ray Region (S17)
Pavel Vrba1, Miroslava Vrbova2, Sergey V. Zakharov3, Vasiliy S. Zakharov3,4 Alexandr Jancarek5, Michal Nevrkla5 1 Institute of Plasma Physics, Academy of Sciences, 182 00 Prague 8, Czech Republic 2 Czech Technical University, Faculty of Biomedical Engineering, 272 01 Kladno,
Czech Republic 3EPPRA sas, Villebon / Yvette, France 4 KIAM RAS, Moscow, Russia 5 Czech Technical University, Faculty of Nuclear Sci. and Phys. Engineering, 115 19 Prague
1, Czech Republic
XUV and EUV Applications with EUV Sources for Metrology (S46) (Invited Paper) Rainer Lebert, Thomas Mißalla, Azadeh Farahzadi, Christoph Phiesel, Urs Wiesemann, and Wolfgang Diete
Bruker Advanced Supercon GmbH, Waltherstrasse 49-51, 51069 Köln-Dellbrück, Germany
2012 International Workshop on EUV and Soft X-Ray Sources
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12:40 PM Workshop Summary and Announcements
Workshop Summary and Announcements (Summary-Source Workshop) Vivek Bakshi, EUV Litho, Inc.
1:00 PM Workshop Adjourned 1:00 Leave for Lunch and Tour
(Wicklow Historic Gaol and area)
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Thursday, October 11, 2012 Location: Newman House, Stephen’s Green, Dublin
Technical Working Group (TWG) Meeting 8:30 AM Breakfast 9:00 AM – 10:00 AM TWG Meeting
2012 International Workshop on EUV and Soft X-Ray Sources
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ABSTRACTS
2012 International Workshop on EUV and Soft X-Ray Sources
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S1
High Repetition Rate Table-top Soft X-Ray Lasers
J. J. Rocca1,2,3, B. Reagan 1,2, Y. Wang,1,2 , D. Alessi, B. M. Luther1,2, K. Wernsing1,2, L. Yin 1,2
, M. A. Curtis 1,2, M. Berrill1,2 , D. Martz 1,2 ,
V.N. Shlyaptsev1,2 , S. Wang 1,2 , F. Furch 1,3, M. Woolston 1,2, D. Patel 1,2, C.S. Menoni 1,2
1 National Science Foundation ERC for Extreme Ultraviolet Science and Technology 2 Electrical and Computer Engineering Department, Colorado State University, Fort
Collins, CO 80523 3 Physics Department, Colorado State University, Fort Collins, CO 80523
We will discuss recent advances in the development of high repetition rate table-soft soft x-
ray lasers resulting from work at Colorado State University that significantly increase the repetition rate and average power of table-top soft x-ray lasers. These advances include the first demonstration of a 100 Hz repetition rate table-top soft x-ray laser, and the
efficient generation of gain-saturated sub-9-nm wavelength picosecond laser pulses of micro joule energy at 1 Hz repetition rate [1].
Gain-saturated lasing was obtained at λ=8.85 nm by collisional electron impact excitation of nickel-like lanthanum ions in a pre-created plasma column heated by a picosecond
optical laser pulse. Furthermore, isoelectronic scaling along the lanthanide series resulted in lasing at wavelengths as short as 7.36 nm. We will also discuss progress in the
development of high repetition rate diode-pumped table-top soft x-ray lasers. Efficient pumping of the soft x-ray driver laser with diode lasers opens the possibility to develop a new generation of more compact soft x-ray lasers capable to operate at significantly
increased repetition rates and larger average powers for applications. We have previously reported the demonstration of a diode pumped soft x-ray laser operating at 10 Hz
repetition rate in the = 18.9 nm line of Ni-like Mo ions using a diode-pumped Yb:YAG chirped-pulse-amplification pump laser system. Recently we have operated this compact laser at 100 Hz repetition rate for the first time to achieve an average power of 0.15 mW,
the highest average power obtained to date from a table-top coherent source at sub-20 nm wavelengths. The increase in photon flux that results from operating compact soft x-ray
lasers at high repetition rates will open up new applications.
1. D. Alessi, Y. Wang, D. Martz, B. Luther, L. Yin, D.H. Martz, M.R. Woolston, Y. Liu, M. Berrill, and J.J. Rocca, “Efficient excitation of gain-saturated sub-9 nm wavelength table-top soft X-ray lasers and lasing down to 7.36 nm”, Physical Review X , 1, 021023 (2011)
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Presenting Author
Jorge J. Rocca is a University Distinguished Professor at Colorado State
University, in the Department of Electrical and Computer Engineering and
the Department of Physics. Professor Rocca’s research concentrates mostly
in the development and physics of compact soft x-ray lasers and their
applications, and in the study of dense plasmas, subjects in which he has
published more than 200 peer review journal papers. His group
demonstrated the first gain-saturated table-top soft x-ray laser using a
discharge plasma as gain medium, and later extended the wavelength of
bright high repetition rate table-top lasers down to 8.8 nm using laser-
created plasmas. Early in his career Rocca was an NSF Presidential Young
Investigator. He is a Fellow of the American Physical Society, the Optical
Society of America, and the Institute of Electrical and Electronics Engineers.
He was the recipient of a Distinguished Lecturer Award from IEEE in 2008,
the Schawlow Prize in Laser Science from the American Physical Society in
2011, and the Willis E .Lamb Award for Laser Science and Quantum Optics in
2012.
2012 International Workshop on EUV and Soft X-Ray Sources
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S2
Extendibility of LPP EUV Source Technology in Higher Power (kW) and Shorter Wavelength (6.x nm) Operation
Akira Endo
Waseda University, Tokyo, Japan
HiLASE Project, Prague, Czech Republic
The basic architecture of double pulse method is explained as the higher CE is available
together with full target mass recovery due to full ionization of injected micro Tin droplets at high repetition rate. Much higher repetition rate is desirable for increase of output
power, and the physical limit on this approach is explained by the plasma behavior in magnetic field. BEUV operation is explained as the extension of the double pulse method to Gd/Tb micro droplets, and expected CE is estimated from recent experiments as
1.5%/0.6% bandwidth.
Presenting Author
Prof. Dr. A. Endo worked in various fields in high power lasers and short
wavelength research, and joined in EUVA to work as a research leader of EUV
light source in 2002. High average power, pulsed laser was the first
requirement. Pulsed CO2 laser was initially tested to generate EUV emission
with surprising positive results. Intensive research showed 20kW average
power available by pulsed CO2 laser architecture. Another issue was to avoid
damage by fast particles from plasma. A suitably designed magnetic field could
guide the plasma flow to a diverter installed outside the vacuum chamber. The
demonstrated method is now under integration by Industry.
He stayed in 2009 in Jena, Germany as the 10th Carl Zeiss Guest Professor to
give a series of lectures on the newly developed EUV source. This lecture
attracted many audiences in University and Companies. This lecture was
summarized in a book chapter as CO2 laser produced Tin plasma light source
as the solution for EUV lithography, Chapter 9, Lithography Edited by Michael
Wang, InTech, February (2010). This article had more than 1000 readers until
the end of 2011.
He is now a guest professor in a research group of laser-Compton X-ray source
in Waseda University, and a research leader of a high average power, pulsed
solid state laser in HiLASE project in Prague, Czech Republic.
2012 International Workshop on EUV and Soft X-Ray Sources
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S3
Microfocus Sources for EUV and X-ray Applications
Alan Michette
Department of Physics, King's College London, Strand, London WC2R 2LS, UK
Applications utilizing short wavelength radiation are becoming increasingly demanding on the properties of the source and the associated optics. It is well known that facilities such
as synchrotrons and free-electron lasers offer exceptional source qualities, but for routine analytical, technical or commercial applications it is widely recognized that more readily
available systems must be developed.
This presentation will summarize the work of the COST Action MP0601 Short Wavelength Laboratory Sources, including source modeling and development as well as the coupling to suitable optical systems. Some exemplar applications will also be described. The talk will
conclude with a look to the future as the new COST Action MP1203 Advanced Spatial and Temporal X-ray Metrology gets underway.
Presenting Author
Alan Michette is a Professor of Physics and the Head of the Physics
Department at King’s College London. He has been carrying out research
into X-ray sources and optics, and their applications, for over 30 years, in
some senses carrying on from previous researchers at King’s such as
Maxwell, Barkla, Franklyn, Wilkins and Hart. His current interests are
related to studies of radiation-induced cancers using microfocus X-ray
sources and novel X-ray optics.
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S10
EUV Lithography: Today and Tomorrow?
Vadim Banine
ASML, The Netherlands
EUV lithography has come a long way over the last two decades starting from small field demonstration systems through full field alpha tool scanners installed in 2006 in CNSE, Albany, USA and IMEC, Leuven, Belgium to EUV followed by multiple pre-production tools
installed at customer locations since 2010.
Starting with historical perspective, mid- and long-term challenges for the source will be reviewed.
EUV can be extended for several nodes by a combination of advanced illumination schemes, higher numerical aperture and potentially new wavelength. Worldwide research
activities supporting this EUV extension will be shared and discussed.
Presenting Author
Dr. Vadim Banine is currently Director of Research at ASML. He has
worked for ASML since 1996 and has held positions of Senior Research
Manager, Head of ASML laboratory and external project co-ordinator for
ASML research department. He received his PhD in 1994 from
Eindhoven University of Technology, The Netherlands (TUE). The
subject of his PhD work was the diagnostics of combustion plasma.
From 1995-96 he did his postdoctoral work at TUE in the Laboratory of
Heat and Mass Transfer. He has over 40 publications and over 100
patens. He is also the winner of ASML patent award.
2012 International Workshop on EUV and Soft X-Ray Sources
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S11
Plasma-based UTA Emission in BEUV & Water Window Spectral Regions
Takeshi Higashiguchi1, Takamitsu Otsuka1, Weihua Jiang2, Akira Endo3, Thomas
Cummins4,
Colm O’Gorman4, Bowen Li4, Deirdre Kilbane4, Padraig Dunne4, and Gerry O'Sullivan4
1Department of Advanced Interdisciplinary Sciences, Center for Optical Research &
Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan
2Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan
3HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 18221 Prague 8, Czech Republic
4School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
We demonstrate the EUV and soft x-ray sources in the 2 to 7 nm spectral region related to
the beyond EUV (BEUV) question at 6.x nm [1-7] and the water window source [8] based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges
to produce intense unresolved transition arrays (UTAs), extending below the carbon K edge (4.37 nm). An outline of a microscope design for single-shot live cell imaging is proposed based on high-Z plasma UTA source, coupled to multilayer mirror optics. We will discuss
the value of x in 6.x-nm BEUV emission to optimize coupling with the recent multilayer mirror developed by FOM. In addition, and we will propose new scheme for a microscope in
water window spectral region. [1] T. Otsuka et al., Appl. Phys. Lett. 97, 111503 (2010); G. Tallents et al., Nat. Photonics 4, 809 (2010). [2] T. Otsuka et al., Appl. Phys. Lett. 97, 231503 (2010). [3] T. Higashiguchi et al., Appl. Phys. Lett. 99, 191502 (2011). [4] B. Li et al., Appl. Phys. Lett. 99, 231502 (2011). [5] T. Cummins et al., Appl. Phys. Lett. 100, 061118 (2012). [6] C. O’Gorman et al., Appl. Phys. Lett. 100, 141108 (2012).
[7] B. Li et al., Appl. Phys. Lett. 101, 013112 (2012). [8] T. Higashiguchi et al., Appl. Phys. Lett. 100, 014103 (2012).
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Presenting Author
Takeshi Higashiguchi is an associate professor. He received his Ph.D. in
engineering from Utsunomiya University. His research activities have
focused on short-wavelength light sources, laser-plasma interaction, and
hybrid laser system.
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S13
Feasibility Study of Microplasma High-brightness EUV Source at 13.5 nm
Takeshi Higashiguchi1, Yoichi Hirose1, Yuhei Suzuki1, Takamitsu Otsuka1, Jun-ichiro
Sugisaka1,
Akira Endo2, Padraig Dunne3, and Gerry O'Sullivan3
1Department of Advanced Interdisciplinary Sciences, Center for Optical Research & Education (CORE), and Optical Technology Innovation Center (OpTIC),
Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan 2HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 18221 Prague 8, Czech
Republic 3School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
We investigated the feasibility of using a microplasma high-brightness EUV source at 13.5 nm as a metrology source. Compared with the HVM case specific requirements for
metrology sources have not yet been specified. The light source needs to be stable, small with an etendue in the order of 0.03 mm2sr, and high-brightness with a few watts of power. The microplasma for a metrology source should be produced to be the order of 10-
20 um with a millijoule per pulse. We show a proof-of-principle experiment by use of a microtarget with a diameter of 10 microns with a thickness of 100 nm, and the results are
supported by numerical simulation.
Presenting Author
Takeshi Higashiguchi is an associate professor. He received his Ph.D. in
engineering from Utsunomiya University. His research activities have
focused on short-wavelength light sources, laser-plasma interaction, and
hybrid laser system.
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S14
Possibility of High-Z Plasma Water Window Sources
Takeshi Higashiguchi1, Takamitsu Otsuka1, Weihua Jiang2, Akira Endo3, Bowen Li4, Deirdre Kilbane4, Padraig Dunne4, and Gerry O'Sullivan4
1Department of Advanced Interdisciplinary Sciences, Center for Optical Research &
Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan
2Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan
3HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 18221 Prague 8, Czech Republic
4School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
UTA (unresolved transition array) emission from highly ionized high-Z materials, such as Sn, Xe, Gd and Tb can be optimized for high conversion efficiencies greater than 1% in the extreme ultraviolet (EUV) spectral region. The UTA is scalable to shorter wavelengths, and
Gd was shown to have a similar conversion efficiency to Sn (13.5 nm) at a higher plasma temperature, with a narrow spectrum centered at 6.7 nm, where a 70% reflectivity mirror
is anticipated. We demonstrate a table-top broadband emission water window source based on laser-produced plasmas. Resonance emission from multiply charged ions merges to produce intense UTAs in the 2 to 4 nm region, extending below the carbon K edge (4.37
nm). An outline of a microscope design for single-shot live cell imaging is proposed based on a bismuth plasma UTA source, coupled to multilayer mirror optics.
Presenting Author
Takeshi Higashiguchi is an associate professor. He received his Ph.D. in
engineering from Utsunomiya University. His research activities have
focused on short-wavelength light sources, laser-plasma interaction, and
hybrid laser system.
2012 International Workshop on EUV and Soft X-Ray Sources
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S15
A Capillary Discharge-preformed Argon Plasma Waveguide for a Coherent Soft X-ray Source
Shohei Sakai1, Takeshi Higashiguchi1, Nadezhda Bobrova2, Pavel Sasorov2, and
Noboru Yugami1
1Department of Advanced Interdisciplinary Sciences, Center for Optical Research &
Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan
2Institude for Theoretical and Experimental Physics, B. Cheremushkinskaya str. 25, 117218 Moscow, Russia
We have reported the argon plasma waveguide produced in an alumina capillary discharge and used to guide ultrashort laser pulses at intensities of the order of 1016 W/cm2 for
coherent soft x-ray radiation by use of soft x-ray laser and/or high order harmonics. The electron density in the plasma waveguide was measured to be 1 x 1018 cm-3, in agreement with one-dimensional MHD simulations. A maximum ion charge state of Ar3+ was measured
in the capillary discharge and also obtained in our MHD simulations. The spectrum of the propagated laser pulse in the Ar plasma waveguide was not modified and was well
reproduced by PIC simulations under an initial ion charge state of Ar3+ in the preformed plasma waveguide. We discuss the possibility of the compact, coherent soft x-ray source in this presentation.
Presenting Author
Shohei Sakai is a Ph.D. student in Department of Innovation Systems
Engineering at Utsunomiya University. His research activities have focused
on terahertz radiation source and laser-plasma interaction. He is working at
Tanaka Scientific Ltd. as a senior engineer and his main charge is R&D of
EDXRF and WDXRF of the sulfur analyzer.
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S16
Concept Study on an Accelerator based Source for 6.x nm Lithography
Udo Dinger1, Diana Tuerke1, Atoosa Meseck2, Michael Patra1, Erik Sohmen1,
Andreas Jankowiak2
1 Carl Zeiss SMT GmbH, Rudolf – Eber - Straße 2, 73447 Oberkochen 2 Helmholtz-Zentrum Berlin für Materialien und Energie GmbH,
Hahn-Meitner-Platz 1, 14109 Berlin
“Beyond EUV (BEUV) lithography” at 6.x nm calls for a source providing very high power in
the 1 kW regime with a very small bandwidth at lowest possible etendue. Present baseline are laser plasma sources based on either Gadolinium or Terbium targets. Recently
accelerator based sources have been brought into discussion as lithography sources in several presentations. However so far not all the special requirements imposed by driving a
lithography tool have been taken into account properly. In this work a scenario for a source based on a SASE‐FEL is presented. The components and requirements are defined to
especially fulfill the needs of lithography and checked for feasibility. In our presentation we will focus on key features like footprint, output power, invest and operational costs in a lithography system and give a rough idea of their numbers.
Presenting Author
2012 International Workshop on EUV and Soft X-Ray Sources
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S17
Capillary Plasma Radiation Source in the Soft X-Ray Region
Pavel Vrba1, Miroslava Vrbova2, Sergey V. Zakharov3, Vasiliy S. Zakharov3,4 Alexandr Jancarek5, Michal Nevrkla5
1 Institute of Plasma Physics, Academy of Sciences, 182 00 Prague 8, Czech
Republic 2 Czech Technical University, Faculty of Biomedical Engineering, 272 01 Kladno,
Czech Republic 3EPPRA sas, Villebon / Yvette, France
4 KIAM RAS, Moscow, Russia 5 Czech Technical University, Faculty of Nuclear Sci. and Phys. Engineering, 115 19
Prague 1, Czech Republic
Plasma dynamics and emission characteristics of pinching capillary discharge simulated by Z*code are presented and compared with experimental results. The investigated setup consisted of capillary with radius R0 = 0.16 cm, length L = 10 cm filled by nitrogen,
connected to capacitor C = 21 nF, charged to U0 = 70 kV. Both calculated and measured current profiles were near to dumped sinus with the peak value ~23 kA and the half period
~150 ns. The output power of emission in the “water window” at the wavelength = 2.88 nm depends on the initial nitrogen pressure. The time dependences of the emitted power in the line have pulse profiles with two remarkable peaks. The highest peak value at the pinch
time was ~1.8 MW at pressure ~100 Pa. The plasma electron temperature 40 eV < Te <
80 eV was noticed in the column with the radius ~ 600 m. The estimated pulse emitted energy 5.5 mJ.sr-1 (~1014 photons.sr-1) corresponds properly to observed experimental
value. Ray tracing inspection along the capillary axis proved reasonable role of self-absorption at the investigated wavelength. The time dependences of plasma parameters in
the capillary centre were used as input data for FLYCH code. The spectra evaluated by the code agree to the measured ones.
Presenting Author
Professor Miroslava Vrbova, graduated in Physical Electronics from the
Czech Technical University in Prague (CTU), received Ph.D. degree in
Quantum Electronics and Optics from the same university. Now, she is
working as a professor of Applied Physics at the Department of Natural
Sciences, CTU- Faculty of Biomedical Engineering.
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S18
Diagnostics and Modeling of Gas Puff Target Laser Plasma Radiation Source
Sarka Vondrova1, Dalibor Panek1, Petr Bruza1, Miroslava Vrbova1, Pavel Vrba2,
Przemyslaw Wachulak3,Frantisek Krejci1, 4, Jan Jakůbek4
1Czech Technical University in Prague, Faculty of Biomedical Engineering, 272 01
Kladno, Czech Republic 2 Institute of Plasma Physics, Academy of Sciences, 182 00 Prague 8, Czech
Republic 3Military University of Technology, Institute of Optoelectronics, 00-908 Warszawa
49, Poland 4 Czech Technical University in Prague, Institute of Experimental and Applied
Physics, 128 00 Prague 2, Czech Republic
Here we present a study of XUV emission characteristics of nitrogen plasma induced by
infrared laser pulse (800 mJ / 7 ns) focused into a gas puff target. Spatial distribution of nitrogen density was determined by EUV radiography at the wavelength 13.5 nm. We used
Gaussian function to approximate the cross-section of the gas puff target in the direction perpendicular to the axis of the nozzle. The value of target mass density was estimated to
be 3.7·10-4 g/cm3 at the distance z = 0.5mm from the nozzle and 4.9·10-4 g/cm3 at z =
0.25 mm from the nozzle. The resulting density profile at the focal region and measured time dependences of laser power were introduced as input data to 2D RMHD (Radiation-
Magneto-Hydro-Dynamic) code Z* (EPPRA s.a.s, France). Spatial developments of nitrogen plasma quantities were modeled. The evaluated electron temperature at the center of gas puff target exceeded the value Te ~ 34 eV. The related peak value of emitted energy
density, in the wavelength region 2.8766 – 2.8867 nm approached the value Qeuv ~ 0.3 J/cm3. The evaluated spatial distributions of emitted energy were compared with the
experimental data obtained with a compact laser-based XUV source (Laser-Laboratory Göttingen e.V., Germany).
Presenting Author
Sarka Vondrova works in the Institute of Optoelectronics (IOE), Military
University of Technology, Warsaw, Poland, in the area of EUV Sources. In
2011, she received her PhD in the department of Biomedical Engineering
Czech Technical University (CTU), Prague, Czech Republic with
specialization in the area of Soft X-Ray and XUV Radiation. She received
her Masters in the department of Electrical Engineering, CTU in Prague,
Czech Republic with specialization in Biomedical Engineering. Her Bachelor
degree in 2008 is from Nuclear Sciences and Physical Engineering CTU in
Prague with a specialization in Laser technology and optoelectronic.
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S19
EUV Emission from Xe gas Target Laser Plasma Pre-ionized with the UV Laser Light
Serguei Kalmykov, Alexey Mozharov, Mikhail Petrenko, Maxim Sasin
Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg, 194021 Russia
To avoid undesirable self-absorption of the EUV-radiation in outer non-ionized gas, density of the Xe
gas-puff target should be of 1018 cm-3 in order of magnitude. Estimations and experiments performed
earlier (Dublin-2011 EUV Workshop, S25) had
demonstrated very slowed primary ionization in the laser plasma generated in such low density target
by means of a standard ND:YAG laser – process of ionization up to Xe+1 took about a half of the laser
pulse.
In the present work, UV excimer laser radiation (λ = 248 nm) is applied as a pre-ionization agent to
accelerate the plasma ionization dynamics and thereby to enhance the EUV output. By now, work
on targeting of both the laser beam foci onto the gas jet has been completed (see photo),
comparative experiments on measuring EUV emission from the laser plasma with and without
the pre-ionization are expected to get start in
August.
Stretched along the beam, the
spark generated by the UV excimer
laser (λ = 248 nm) at reduced
pulse energy (≈ 60 mJ). A black
hole just behind the spark (at the
distance of 1 mm) is the 1.1 mm-
diameter output nozzle orifice.
2012 International Workshop on EUV and Soft X-Ray Sources
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Presenting Author
Serguei Kalmykov was born March 6, 1939 in Leningrad, Soviet Union,
in 1962 graduated from the Polytechnical Institute (now St. Petersburg
State Polythechnical University) and had been put in the research staff
of the Ioffe Institute (St. Petersburg) where I continue working until
now. Candidate of math sciences (physics/mathematics) degree from
1980 (this Russian scientific degree is approximately equivalent to PhD
in Anglo-Saxon countries). Between 1962 and 2002 I was involved into
the high temperature plasma and fusion area (general tokamak physics,
magnetic confinement, transport processes) but then, in 2007, changed
it for the laser plasma EUV source physics. Author/coauthor of
approximately 60 scientific publications.
2012 International Workshop on EUV and Soft X-Ray Sources
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S20
Direct Diagnostics Concept for High Power CO2 Laser at the LPP Focus Spot
Kazuyuki Sakaue, Yasufumi Yoshida, Ryo Sato, Masakazu Washio, Akira Endo
Research Institute for Science and Engineering, Waseda university 3-4-1 Okubo, Shinjuku, Tokyo 169-855 Japan
In the Laser Produced Plasma (LPP) EUV source, stability of CO2 laser, which produces plasma, is the most important issue. The required CO2 laser exceeds more than 100 kHz
repetition 200 mJ pulse with 100 spot and 1ns pulse duration at the plasma point. Direct diagnostics of such a high power pulse cannot be achieved by the recent
technologies. Position, energy, and timing stabilities are necessary for stable EUV source, moreover, the ideal laser spot profile is also needed for higher conversion efficiency (CE).
This presentation proposes the unique diagnostics for such high power laser pulses at the focus point.
This technique based on laser-Compton scattering with a very small spot electron beam. Focused electron beam, of about 10micron size, is scanned over the laser spot as the SEM,
the laser-Compton scattering photon has the information of the high power laser pulses. If we scanned the electron beam from various direction, the laser focus profile can be
obtained like a CT image. We believe that this technique can provide the valuable information for stabilizing and
optimizing the EUV source. The concept of this diagnostics, simulation studies of focused scanning electron beam, and future plans will be presented at the conference.
Presenting Author
Kazuyuki Sakaue is Assistant Professor of Applied physics department at
Waseda University. He received a Ph. D degree in Accelerator Science from
Waseda University. He has been active in the area of electron accelerators
and laser-beam interactions for over 8 years. His current research involves
study of high quality electron beam generation and the laser enhancement
super-cavity system for upgrading the laser-beam interactions.
2012 International Workshop on EUV and Soft X-Ray Sources
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S21
Whole Cell Cryogenic Soft X-ray Tomography with a
Laboratory Light Source
D.B. Carlson1, J. Gelb2, V. Palshin2 and J.E. Evans1,3,*
1Dept. of Molecular and Cellular Biology, University of California at Davis, Davis, CA, USA
2Xradia, Inc., Pleasanton, CA, USA 3Pacific Northwest National Lab, Environmental Molecular Sciences Lab, Richland,
WA, USA
Identifying the precise location of individual proteins or organelles within the cellular
context has been a long held ambition of both structural and molecular biologists. Correlative light and electron microscopy attempts to address this goal by combining fluorescence data of specifically labeled proteins with ultrastructural details derived from
transmission electron microscopy [1]. Unfortunately, to allow the transmission of electrons for high-resolution imaging, cellular material must be sectioned into thin slices thereby
removing the direct link to whole cell fluorescence data. Recent advances in synchrotron based x-ray microscopy have empowered a third approach that bridges the spatial scales between fluorescence and electron microscopy [2].
While traditionally limited to synchrotron facilities alone, new advancements in compact light sources are now making soft x-ray microscopy available for routine laboratory
characterization [3]. We will present the first multimodal correlative results from a novel soft x-ray microscope that incorporates a compact light source based on the Energetiq EQ-10 platform operating at 430 eV photon energy. The results highlight the ability of this
approach for enabling a better understanding of the structure/function relationship of frozen hydrated whole cells up to 5 micrometers thick at spatial resolutions up to 50 nm. References 1. D.B. Carlson and J.E. Evans, (2011). “Low Cost Cryo-Light Microscopy Stage Fabrication for Correlated Light/Electron
Microscopy,” J Vis Exp. 52, e2909. 2. C. Larabell and M. A. Le Gros, (2004) “X-ray tomography generates 3-D reconstructions of the yeast, Saccharomyces
cerevisiae, at 60-nm resolution,” Mol. Bio. of the Cell 15, pp. 957-962. 3. D.B. Carlson, J. Gelb, V. Palshin and J.E. Evans “Laboratory-Based Cryogenic Soft X-ray Tomography with Correlative
Cryo-Light and Electron Microscopy” Microsc. & Microanal. IN PRESS 4. The aid of Dr. Steve Horne at Energetiq Technologies, Inc. (Woburn, MA, USA) is gratefully acknowledged. A portion of
this work was performed at the Pacific Northwest National Laboratory which is operated by Battelle Memorial Institute for the U.S. Department of Energy under Contract No. DE-AC05-76RL01830. The majority of funding support for this research came from NIH grant number 5RC1GM091755 and 2R44RR022488.
2012 International Workshop on EUV and Soft X-Ray Sources
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Presenting Author
James Evans is a Staff Scientist with Pacific Northwest National Laboratory.
Dr. Evans obtained his PhD is Biochemistry from the University of California
Davis with a focus on cryogenic aberration corrected electron microscopy.
His current areas of research involve developing methods for improved
multiscale imaging of biological structure and dynamics using electrons and
x-rays including laboratory based cryogenic soft x-ray tomography,
multimodal correlative microscopy and in situ aberration corrected dynamic
transmission electron microscopy.
2012 International Workshop on EUV and Soft X-Ray Sources
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S22
In-situ Diagnostics for Plasma based Extreme Ultraviolet Sources
T. W. Versloot, F.T. Molkenboer, H.H.P.Th. Bekman, N.B. Koster, E. te Sligte, R. Verberk, R.C.M. Pohlmann, F.H. Elferink
TNO Delft, Stieltjesweg 1, 2628 CK, Delft, the Netherlands
Most sources for extreme ultraviolet (EUV) radiation are based on line emission from high temperature, high density plasmas. The obtained conversion efficiency from input power to
the observed in-band EUV power will depend, among others, on the achieved plasma conditions. In order to further increase the EUV output, it is therefore vital to determine
these plasma operating conditions. Currently, only limited direct diagnostic information from the plasma is available due to the harsh operating environment, short pulse duration and limited accessibility. Furthermore, in most cases dedicated diagnostics are relatively
complex, spatially localized and costly.
At TNO we have developed several diagnostics that can be operated reliably within a source environment, e.g. infrared cameras and RGA’s. Recently we have also integrated several diagnostics into a single small size device that can be used for in-situ measurements. This
prototype consists of a Langmuir probe, heat flux sensor, Faraday cup, photodiodes (UV/VIS) and a PT100. The sensor head can be positioned by a semi-rigid bellow and is
mounted to either a vacuum compatible stand-alone data logger or flange feed-through. Future developments are aimed towards long-duration testing this proof-of-principle device in an EUV environment and expanding the set of diagnostics.
Presenting Author
Thijs Versloot graduated from Twente University (Enschede, Netherlands)
with a degree in Applied Physics in 2007. He received a PhD in Fusion
Science and Technology in 2011 from the Eindhoven University of
Technology on experimental diagnostic work carried out at the JET tokamak
in the United Kingdom. His research is focused on experimental plasma
physics, plasma diagnostics, plasma surface interactions and development
of various types of plasma sources.
2012 International Workshop on EUV and Soft X-Ray Sources
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S23
Measurement of Spectra in Water- window Wavelength Region
J. Novak1, M. Nevrkla1, A. Jancarek1, M. Vrbova2, P. Vrba3
1Czech Technical University, Faculty of Nuclear Sciences and Physical Engineering,
115 19 Prague 1, Czech Republic 2Czech Technical University, Faculty of Biomedical Engineering, 272 01 Kladno,
Czech Republic 3Institute of Plasma Physics, Academy of Sciences, 182 00 Prague 8, Czech Republic We demonstrate spectra measurement of nitrogen, argon and carbon dioxide as a possible source of XUV radiation in “water window” (2.2 - 4.4 nm) region. Capillary discharge
system with 10 cm long, 3.2 mm inner diameter alumina capillary and peak current amplitude pulse of 21 kA was used. Our spectroscopic system has a resolution 0.03 nm and is composed from a silicon nitride free-standing transmission diffraction grating with 100
nm period and Reflex BICCD camera with frame size 512x512 pixels.
To find the best conditions for maximum output energy per steradian in one pulse measurement for eight different pressures were made for each gas. We recognized strong emission at these wavelengths 2.88 nm in nitrogen N VI, 1s2 - 1s2p, in argon 3.82 nm Ar
X, 2s22p5- 2s22p43d and 3.83 nm Ar XI, 2s22p4 - 2s22p33s, carbon dioxide 3.34 nm C V, 1s2 - 1s4p, 3.37 nm C VI, 1s - 2p and 4.03 nm C V, 1s2 - 1s2p. As a possible “water window”
source could be used nitrogen at 2.88 nm, argon at 3.82 and 3.83 nm and carbon dioxide at 3.34 nm, 3.37 nm and 4.03 nm.
Presenting Author
2012 International Workshop on EUV and Soft X-Ray Sources
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S24
Characterization of Capillary Discharge Water-Window Radiation Source
Michal Nevrkla1, Jan Novak1, Alexandr Jancarek1, Pavel Vrba2, Miroslava Vrbova3
1 Czech Technical University in Prague, Faculty of Nuclear Sciences and Phys. Engineering, 115 19 Prague 1, Czech Republic
2 Institute of Plasma Physics, Academy of Sciences, 182 00 Prague 8, Czech Republic
3Czech Technical University in Prague, Faculty of Biomedical Engineering, 272 01 Kladno, Czech Republic
Intense XUV radiation in the “water-window” wavelength region, i.e. 2.3 - 4.4 nm, was generated by a Z-pinching capillary discharge in Nitrogen and Argon. The current driver is
capable to deliver 23 kA in a pulse with rise-time of 50 ns into a 100 mm long, 3.2 mm diameter capillary. The output XUV radiation was characterized by following diagnostic
methods: The time evolution of radiation emission from the capillary discharge Z-pinching Nitrogen and Argon plasma was measured by a XUV PIN diode in order to get radiation intensity and energy per pulse. Beam profile and divergence were measured via time-
integrated image captured by a soft X-RAY BI-CCD camera. The radiation source size was found via a pinhole image. Spectral characteristics were obtained using a SiNx transmission
grating. A 0.5 m Titanium filter was used to select the wavelength region from 2.73 nm to approx. 6 nm. Optimization of initial gas pressure and discharge current amplitude was performed in order to find the maximal radiation intensity, energy per pulse, and maximal
driver efficiency. Achieved output radiation intensities and energy in water-window wavelength region are: ~ 0.1 MW/srad (10 ns FWHM), ~ 3 mJ/srad/pulse (60 ns FWHM) in
Nitrogen, and ~ 0.5 MW/srad (15 ns FWHM), ~ 20 mJ/srad/pulse (70 ns FWHM) in Argon. Driver repetition rate is 5 pps.
Presenting Author
Michal Nevrkla, is a PhD. student of Faculty of Nuclear Sciences and
Physical Engineering, Czech Technical University in Prague.
2012 International Workshop on EUV and Soft X-Ray Sources
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S25
Properties of High-intensity EUV & Soft-X Radiation Plasma Sources
Vasily S. Zakharov1,2, Sergey V. Zakharov 1,2,3, Peter Choi1
1EPPRA sas, Villebon sur Yvette, France in collaboration with KIAM RAS, Moscow,
Russia 2NRC Kurchatov Institute, Moscow, Russia
3JIHT RAS and SRC RF TRINITI, Moscow, Russia The high intensity radiation in plasma light sources is produced by multicharged ion non-
equilibrium plasma. The innovative hybrid 2-3D computational code based on the Z+
code
and its commercially available version Z+
BME at EPPRA are further improved under
international collaborative project FIRE FP7 IAPP to model radiating plasmas in experimental and industrial facilities using a hybrid approach including fast particles and plasma dynamics in an electromagnetic field, advanced atomic physics models and the
spectral radiation transport. The code is used to model laser-produced plasma and discharge-produced plasma to understand current physical processes and to optimize the
sources by brightness and delivered power of EUV & soft-X radiation for lithographic and metrology applications. The radiation plasma dynamics, the spectral effects of self-absorption in laser-produced plasma and discharge-produced plasma are considered. The
radiance and conversion efficiency of laser energy to EUV radiation in tin LPP is discussed. The generation of fast electrons triggering a discharge and an enhancement of the radiance
of a fast micro-plasma pulsed discharge created in a capillary wall confined structure is optimized. Without using an external physical optics, the EUV power can be focused by quasi-periodical self-consistent wave plasma structure. The power and brightness to
required values can be increased through spatial and/or temporal multiplexing of low-etendue individual units. Static and dynamic combinations of 4 sources are considered.
Fundamental understanding of Gd plasma emission with effects of radiation self-absorption has been done to move to 6.x nm waveband.
This work was performed in collaboration with in collaboration with KIAM RAS, Moscow, Russia.
2012 International Workshop on EUV and Soft X-Ray Sources
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Presenting Author
Dr. Sergey V. Zakharov graduated from the Moscow Institute of Physics and
Technology. He received the doctor degree in physical-mathematical
sciences from Kurchatov Institute of Atomic Energy, Moscow, Russia. In
1981-2005 he joined Troitsk Institute of Innovation and Fusion Research
(TRINITI), Russia, in 1981, as a Head of the theoretical laboratory. In 1995-
1998 he was a Professor of Moscow State Technology University, Russia. In
1993-1999 he was Director of Center of High Technologies ZENITH,
Dolgoprudniy, Russia. Since 2005 he joined the Russian National Research
Centre Kurchatov Institute as a Leading Scientist. His works concern plasma
turbulence theory, nonlinear waves, charged particle beams, radiation-
magnetohydrodynamics and non-equilibrium plasma theory in HEDP and
ICF. For works on interaction of high power electron beams with dense gas
he was rewarded the State Prize for young scientists and engineers in 1987.
For researches on high energy density physics and radiating multicharged
ion plasma he was rewarded the Great Government Reward in 1997. In
1997-1998 he joint Ecole Polytechnique, France as an Invited Senior
Researcher. Since 1999 he joined EPPRA SAS, France, as a Principal
Scientist and a Product manager. In 2009-2012 he also held the position as
a Principle Scientist at NanoUV SAS, France, responsible on theory and
modelling. Since 2010 he also joined with Joint Institute of High
Temperatures of RAS, Moscow, Russia. He works on the theory of non-
equilibrium heavy-ion plasmas and modelling of discharge and laser
produced plasma radiation sources, in particular also for EUV lithography.
Under his leadership the radiation-magnetohydrodynamic codes ZETA and
Z* were created and are being developed. He has more than 250 scientific
publications.
2012 International Workshop on EUV and Soft X-Ray Sources
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S26
Laser-initiated Discharge-produced Plasma Ablated from Liquid Metal Electrodes
Vasily S. Zakharov1*
, Larissa Juschkin2
, Sergey V. Zakharov 1*+
, Gerry O’Sullivan3,
Emma Sokel3, Isaac Tobin4
1
EPPRA sas, Villebon sur Yvette, France in collaboration with KIAM RAS, Moscow, Russia 2
RWTH Experimental Physics, Aachen, Germany 3 University College Dublin, Ireland
4 Trinity College Dublin, Ireland * also with NRC Kurchatov Institute, Moscow, Russia
+
also with JIHT RAS and SRC RF TRINITI, Moscow, Russia Laser-initiated discharge produced plasma system has been studied as a viable approach
for the EUV lithography light source at 13.5 nm wavelength. The source is based on a discharge in tin or galinstan vapor produced by laser pulse between rotating disk electrodes. This paper focuses on the results of the computer modelling of that laser-
induced discharge with the electrical circuit characteristics and laser beam parameters similar to the used in the experiment. Z*-code comprising recent advances in atomic
physics and radiation-magnetohydrodynamics is used under international collaborative project FIRE in the framework of FP7 IAPP to model laser- and discharge-produced plasma dynamics and emission. Complex consideration of radiation from unresolved transition
arrays includes the model of non-equilibrium ionization in plasma of multicharged ions based on detailed kinetic equations resolution with major electon-ion interaction processes
taken into account. The radiation-plasma dynamics and the spectral effects of self-absorption in laser produced plasma and discharge produced plasma are considered. The simulation results are compared with experimental data. The detailed physics of the effects
taking place in the laser-initiated discharge is discussed.
Presenting Author
2012 International Workshop on EUV and Soft X-Ray Sources
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S27
2D PIC Modeling of the EUV Induced Hydrogen Plasma and Comparison to the Observed Carbon Etching Rate
D.I. Astakhov1,3*, W.J. Goedheer1, D.V. Lopaev2, V.V. Ivanov3, V.M. Krivtsun3,
O. Yakushev3, K.N. Koshelev3, and F. Bijkerk1,4
1 FOM Institute DIFFER - Dutch Institute for Fundamental Energy Research, P.O.
Box 1207, 3430 BE Nieuwegein, The Netherlands
2 Institute of Nuclear Physics, Moscow State University, Russia
3 Institute for Spectroscopy, Russian Academy of Sciences, Troitsk, Russia
4 MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
The interaction between an EUV driven hydrogen plasma and a carbon covered surface was investigated using 2D PIC modeling and results were compared with experimental
observations. The plasma is formed due to ionization of a low pressure hydrogen gas by the EUV photons and the photoelectrons from the surface. This results in ion fluxes to the surface, leading to the surface etching. We model the evolution of the plasma during and
after the EUV pulse and obtain the energy resolved ion fluxes from the plasma to the surface. The carbon etching rates observed at various experimental conditions and
estimated from computed ion fluxes for the same conditions agree under assumption that the etching yield is close to one carbon atom per incoming hydrogen ion.
Presenting Author
D.I. Astakhov is a PhD student in the nanolayer Surface & Interface physics
(nSI) department in Dutch Institute for Fundamental Energy Research
(DIFFER). His research interest is in modeling of cold plasmas. Received
M.S. from Moscow Institute for Physics and Technology in 2009.
2012 International Workshop on EUV and Soft X-Ray Sources
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S28
High Brightness, High-average Power Picosecond Thin Disc Laser Program to Specific Requirements from Short Wavelength
Light Sources
Taisuke Miura, Michal Chyla, Martin Smrž, Patricie Severová, Ondřej Novák, Akira Endo, and Tomáš Mocek
HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 182 21 Prague 8, Czech
Republic
Thin disc laser is the best solid state laser architecture to realize high brightness,
high average power, and fast repetition rate picosecond pulses with precise spatial
stability. HiLASE project is started from September 2011 and one program is aiming at achieving 500 W high beam quality pulses by this technology in the
picosecond pulse duration at 100 kHz. Major applications are in the short wavelength light sources, like pre-pulse for dispersion of droplet target, micro
plasma for metrology sources, HHG and RF photocathode illumination. Generally, thermally induced OPD (optical phase distortion) of thin disk limits the ultrashort
pulse output up to few hundreds of watts, and degrades the pointing stability. We designed in-situ transient OPD measurement technique based on a precise
wavefront sensor to compensate the OPDs and to achieve 500 W output with excellent spatial characteristics. The talk gives the overview of the program and
shows the recent experimental progress.
Presenting Author
Taisuke Miura is a senior researcher of the HiLASE Project. He received his
Ph.D. in engineering from Keio University. His present research activities
are focused on high power ultrashort pulse generation based on Yb-doped
thin disk laser technology.
2012 International Workshop on EUV and Soft X-Ray Sources
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S29
Alternative Future 6.x nm EUV Sources from Strong In-band Line Emission
Thomas Cummins1, Takamitsu Otsuka2, Tony Donnelly1, Weihua Jiang3, Akira Endo4, Padraig Dunne1, Gerry O’Sullivan1 and Takeshi Higashiguchi2
1School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
2Department of Advanced Interdisciplinary Sciences, Center for Optical Research & Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya
University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan 3Department of Electrical Engineering, Nagaoka University of Technology, Kami-
tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan 4 HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 182 21 Prague 8, Czech
Republic
Research is proceeding into developing a light source for advancing beyond extreme ultraviolet (BEUV) as a feasible future lithography source. In this work we investigate possible alternative line emitters at 6.x nm due to the current uncertainty on the precise
wavelength of multilayer mirrors. Photoemission spectroscopy of laser produced phosphorus (P) plasma was observed. By irradiating P targets, we demonstrate a viable
alternative BEUV source at 6.x nm from strong line emission observed around 6.6 nm. Given that specific wavelengths of multilayer collector optics are not yet set, this could prove useful as a future source. COWAN code calculations were used to fit experimental
spectra and show BEUV emission of P resulting mainly from the 2p5 – 2p43d transition array of the P VII ion. Calculations of charge state distributions of P plasma show that emission
can be optimized at an electron temperature of around 40-50 eV, meaning optimal emission can be achieved at lower plasma temperatures than required for Gd or Tb laser produced plasmas. Comparing spectra of P with both Gd and Tb shows the peak emission is
better suited to the reflectivity curves of currently available multilayer optics. Calculations of emission from Ne plasma also show its potential as a short wavelength source.
Presenting Author
Thomas Cummins is a 3nd year PhD student. He graduated with a B.Sc. in
Applied Physics from Dublin City University in 2009 and joined the
Spectroscopy group of University College Dublin in September 2009 as a
PhD student. His research interests include laser produced plasma for
development of Extreme Ultraviolet light sources, laser Sn plasma
interaction and shorter wavelength BEUV sources. His project supervisor is
Prof. Padraig Dunne.
2012 International Workshop on EUV and Soft X-Ray Sources
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S30
EUV Emission from Laser-triggered Z-pinch Discharge
Isaac Tobin1, Larissa Juschkin2,3, Fergal O’Reilly2,
Paul Sheridan4, Emma Sokel2, James G. Lunney1
1School of Physics, Trinity College Dublin, Dublin 2, Ireland. 2School of Physics, University College Dublin, Belfield, Dublin 4, Ireland.
3Department of Physics, RWTH Aachen University, Steinbachstr. 15 D-52074 Aachen, Germany.
4Newlambda Technologies, UCD Science Centre North, Belfield, Dublin 4, Ireland.
Current state-of-the-art prototype extreme ultraviolet (EUV) sources for lithography utilize
tin plasma as the emitting material. We have compared the EUV emission characteristics at 13.5 nm for tin and galinstan in a laser-triggered Z-pinch discharge. Galinstan is a metal
alloy (78.35% Ga, 14.93% In, 6.72% Sn) which is liquid at room temperature. The discharge source consists of two disc electrodes which rotate in shallow baths of liquid
metal, and are thus coated with metal. A nanosecond laser pulse is used to form a laser produced plasma on one electrode. This plasma expands rapidly into the electrode gap and triggers a weakly damped discharge with a period of 0.6 µs and a peak current of 17 kA.
The laser energy is adjusted to ensure that Z-pinching occurs at the first maximum of the discharge current.
The EUV emission was measured using an absolutely calibrated time integrating EUV spectrograph and in-band EUV filtered photodiode. The source was measured using EUV
imaging and the plasma outflow was recorded using a Faraday cup ion detector. The energy conversion efficiency (CE) into 2π sr in a 2% band at 13.5 nm is found to be 0.22% for tin
and 0.089% for galinstan for a 4 J discharge. Relative to tin the EUV emission for galinstan is higher than expected according to the percentage of tin, which may be due to the influence of optical opacity in the tin discharge.
Presenting Author
2012 International Workshop on EUV and Soft X-Ray Sources
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S31
Recent Progress on High Brightness Source Collector Module for EUV Mask Metrology
Paul Sheridan1, Kenneth Fahy1, Padraig Dunne2, and Fergal O’Reilly2
1NewLambda Technologies Ltd, Science Center North, Belfield, Dublin 4, Ireland
2 UCD School of Physics, UCD, Stillorgan Rd, Dublin 4, Ireland
NewLambda Technologies (www.NewLambda.com) are developing a high brightness source collector module for EUV mask metrology applications. The collector optic is a liquid metal
coated ellipsoid section. The optic rotates slowly to maintain a uniform and stable thickness of liquid metal over the interior surface. The source is a laser produced plasma which uses
the same liquid metal as the collector. This allows close proximity of the collector to the source without need for debris mitigation before the collector. Thus the module is being designed to deliver a clean, debris-free, high brightness source of 13.5 nm photons to
match industry demands. We report on recent results from our prototype system.
Presenting Author
Paul Sheridan is a founding member of NewLambda Technologies. He
received his Ph.D. in 2008 from UCD Dublin for work on double photo-
electron spectroscopy. Since then he has worked on the development of
EUV sources and collector optics. Previously he received his MSc in the
development of novel targets for laser produced plasma EUV sources. He
has over 10 years design experience of vacuum systems and vacuum
automation.
2012 International Workshop on EUV and Soft X-Ray Sources
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S32
A Tunable Beyond Extreme Ultraviolet Source at 6.x nm based on a Laser-produced Plasma from a High-Z Target Mix
Colm O’Gorman1, Takamitsu Otsuka2, Weihua Jiang3, Akira Endo4, Bowen Li1,
Thomas Cummins1, Padraig Dunne1, Emma Sokell1, Gerry O’Sullivan1, and Takeshi Higashiguchi2
1School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
2Department of Advanced Interdisciplinary Sciences, Center for Optical Research &
Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan
3Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan
4 HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 182 21 Prague 8, Czech Republic
An EUV source with tunable wavelength properties is demonstrated by mixing of the adjacent high-Z elements, Gd and Tb, in a complex target. The targets are irradiated by
Nd:YAG lasers of pulse width 10 ns and 150 ps and their spectral emission in the 6.x nm region is observed. Emission from the complex target is compared to emission from pure
Gd and Tb plasmas. It is shown that the spectral profile from the complex target is not simply an addition of emission from the two individual elements and that the change in
profile is due to opacity effects. The emission is compared to theoretical spectra based on Cowan code calculations [1] coupled with a collisional radiative model [2]. It is envisaged that this tunable wavelength source could be matched to the reflectivity peak of a
multilayer mirror for the development of an EUV source for lithography. References [1] R. D. Cowan, The Theory of Atomic Structure and Spectra, University of California Press, Berkeley (1981). [2] D. Colombant and G. F. Tonon, J. Appl. Phys. 44, 3524 (1973).
Presenting Author
Colm O' Gorman is a PhD student with the Atomic, Molecular and Plasma
Physics group in UCD. He received his B.Sc in Physics from University
College Dublin in 2009. His research activities have focused on EUV
emission spectroscopy and ion spectroscopy of laser produced plasmas.
.
2012 International Workshop on EUV and Soft X-Ray Sources
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S33
Emission Properties of Non-equilibrium Zirconium Plasma in Soft X-ray Region
Vasily S. Zakharov*, Sergey V. Zakharov *+
EPPRA sas, Villebon sur Yvette, France in collaboration with KIAM RAS, Moscow, Russia
* also with NRC Kurchatov Institute, Moscow, Russia + also with JIHT RAS and SRC RF TRINITI, Moscow, Russia
Zirconium-based plasmas are considered as a source of soft X-ray emission in water window waveband alongside with nitrogen- and bismuth-based radiation plasma sources.
Such discharge and laser produced plasmas used in soft X-ray (and EUV) sources are in non-equilibrium state as a rule. This leads to a mismatch between the actual conditions of the plasma and its theoretical/computational estimations because of different effects like
non-thermal electron distribution, self-absorption etc. leading to changes in ionization states, state populations, emission intensity and spectrum. In the report the radiance and
emission properties of non-equilibrium zirconium plasma is examined and the optimal emission conditions for soft X-ray emission in water window region are explored. Kinetic parameters for non-equilibrium plasma including major inelastic ion interaction processes
with non-thermal electrons and radiation, emission and absorption data are obtained in the approach based on Hartree-Fock-Slater (HFS) quantum-statistical model and distorted
waves approximation. Modeling of plasma properties and emission is performed by using RMHD Z* code.
Presenting Author
2012 International Workshop on EUV and Soft X-Ray Sources
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S34
Dual Laser Plasma Photoabsorption Studies Of Gadolinium In The Extreme Ultraviolet Region
Paddy Hayden, C. Fallon, T. J. Kelly and J. T. Costello
School of Physical Sciences/National Centre for Plasma Science and Technology,
Dublin City University, Glasnevin, Dublin 9, Ireland
The characteristic extreme ultraviolet (EUV) emission from laser produced plasmas depends
critically on the distribution of (highly charged) ion stages and the distribution of excited states within each charge state or ion stage. A key limitation on conversion efficiency (CE) of the incident laser pulse energy into useable EUV radiation, especially for solid targets,
arises from the absorption of EUV radiation emitted from the hot laser plasma core by more lowly charged ions in the cooler peripheral regions of the plasma – in summary opacity.
This presentation will be focused on computing and measuring the EUV absorption spectra of atoms and lowly charged gadolinium ions. The Gd absorption spectra, obtained using the well established pump-probe technique, ‘Dual Laser Plasma Photoabsorption (DLPP)’ where
one laser plasma acts as the ‘sample plasma’ while the other constitutes the probing EUV continuum source, will be compared to relativistic time dependent local density
approximation calculations to estimate the absolute photoabsorption cross-sections.
Presenting Author
Paddy Hayden is a Postdoctoral Research Fellow in the National Centre for
Plasma Science and Technology at Dublin City University. He received his
PhD from University College Dublin in 2007 studying atomic and plasma
physics processes in plasma based extreme ultraviolet light sources. He
was awarded an Irish Research Council for Science, Engineering and
Technology postdoctoral research fellowship immediately after receiving his
doctorate degree and joined with Professor J. T. Costello’s group at DCU.
Dr. Hayden also collaborated with many university-based researchers,
small enterprises and multinational companies throughout Europe, Asia and
the United States. He has co-authored more than 30 scientific journal
articles, book chapters, industrial technology transfer reports and patents in
the fields of laser-produced plasma applications, laser induced breakdown
spectroscopy (LIBS), plasma diagnostics, plasma-facing components and
the interaction of intense Free Electron Laser (FEL) extreme ultraviolet light
with matter. While maintaining broader research interests, his main focus is
currently on the design and implementation of novel extreme ultraviolet
light sources as part of a Science Foundation Ireland Investigator Grant
(No. 02/IN.1/I99); a collaboration between UCD, DCU and TCD.
2012 International Workshop on EUV and Soft X-Ray Sources
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S35
Identification of Atomic Resonances for Enhancement of High Harmonic Generation in Laser-produced Plasmas
R.Stefanuika, N. Krstulovica, M. Mahmoadb, P. Dunnea, G. O’Sullivana
a) School of Physic, University college Dublin, Ireland b) Institute Of Lasers for postgraduate studies, University of Baghdad, Iraq
In recent years the generation of high harmonic radiation (HHG) in laser produced plasmas has been reported. One of the noteworthy features of this process is the enhancement of
harmonics that coincide with resonances in the spectrum of atoms or ions in the plasma [1]. We report on the potential of new, wide resonances in the 40 nm region of a range of
elements suitable for the enhanced HHG of the 19th or 21st harmonic of a Ti:Sapphire laser. The laser has a central wavelength of 800 nm, pulse energy of 30 mJ and pulse duration of 30 fs. The resonances were observed using the dual-laser photoabsorption technique using
a 1 m normal incidence spectrometer which is sensitive in the 20-200 nm region [2]. Using the Time Dependent Local Density Approximation (TDLDA) the resonance cross sections
were calculated for comparison with experimental results. These wavelengths are of interest for surface studies in materials science [3].
References [1] R.A Ganeev, Harmonic generation in laser-produced plasmas containing atoms, ions and clusters: a review, Journal of Modern Optics 59:5, 409-439 [2] D.A. LIBERMANI, A.Zangwill “A Relativistic Program For Optical Response In Atoms Using A Time Dependent Local Density Approximation.” Computer Physics Communications 32 (1984) 75-82 North-Holland, Amsterdam [3] T. Higashiguchi et al Characteristics of extreme ultraviolet emission from a discharge-produced potassium plasma for surface morphology application APPLIED PHYSICS LETTERS 96, 131505 2010
Presenting Author
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Electrodeless Z-PinchTM EUV Source for Next Generation EUV Metrology
Deborah Gustafson, Stephen F. Horne, Matthew M. Besen, Donald K. Smith, Matthew J. Partlow, Paul A. Blackborow
Energetiq Technology, Inc., 7 Constitution Way, Woburn, MA, USA 01801
With EUV Lithography systems shipping the requirements for highly reliable EUV sources for mask inspection and resist outgassing are increasing. The sources needed for
metrology applications are very different than that needed for lithography, brightness is the key.
In this presentation we will present a unique source technology being reviewed at Energetiq to address the critical source brightness issue. The Electrodeless Z-pinch technology will be
shown to be capable of delivering brightness levels sufficient to meet the HVM requirements of AIMS and ABI and potentially API tools. The high brightness EUV plasma
is modeled to have a brightness of up to 100 W/mm^2-sr. We will explain the source design concepts, discuss the expected performance and present the modeling results for the new design.
We will also address the need for the next generation source requirements of 6.x nm. We
will present results utilizing a higher power electrodeless Z-pinch source to enable research and development of resists and optics at 6.7 nm.
Presenting Author
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A Commercial Laboratory Soft-X-ray Source for Water Window Microscopy
Stephen F. Horne, Matthew M. Besen, Donald. K Smith
Energetiq Technology, Inc., 7 Constitution Way, Woburn, MA, USA 01801
Beginning in 2006, Energetiq Technology Inc. began development [1] of a soft x-ray source
based on our commercially successful EUV source [2], based on a unique electrode-less Z-pinch design. Operating in Nitrogen, the source produces up to 400 mW of radiation at
2.88 nm (430 eV) [3]. The source has been used as an illuminator for our own demonstration water-window microscope, and has been successfully integrated by Xradia, Inc. (Pleasanton, CA, USA) with their cryo-tomo-capable soft x-ray microscope, the
UltraXRM-S/L220c. While laboratory demonstrations of microscopes driven by table-top x-ray sources have been done [4], this is the first commercially available instrument of this
type. We will present detailed performance data for the source.
1. Supported by NIH grants 5R44RR022488-03, 5R44RR023753-03 and 2R44RR022488-04 2. S. F. Horne, M. M. Besen, D. K. Smith, P. A. Blackborow, and R. D’Agostino, “Application of a high-brightness
electrodeless Z-pinch EUV source for metrology, inspection, and resist development,” Proc. SPIE, 6151, 201-210 (2006).
3. D. Smith, M. Partlow, and S. Horne, "Inductively Driven, Electrodeless Z-pinch Sources for EUV and Soft X-ray Applications," in Frontiers in Optics, OSA Technical Digest (Optical Society of America, 2011), paper FMJ4.
4. H. M. Hertz, O. von Hofsten, M. Bertilson, U. Vogt, A. Holmberg, J. Reinspach, D. Martz, M. Selin, A. E. Christakou, J. Jerlström-Hultqvist, and S. Svärd, "Laboratory cryo soft x-ray microscopy," Journal of Structural Biology, vol. 177, no. 2, pp. 267-272, Feb. 2012.
Presenting Author
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Spectral Characterization of XUV Sources based on Plasmas Induced by Laser and Capillary Discharge
P. Kolar1, D. Panek1, M. Vrbova1, M. Nevrkla2, P. Vrba3, and A. Jancarek 2
1Czech Technical University in Prague, Faculty of Biomedical Engineering, Nam.
Sitna 3105, 272 01 Kladno, Czech Republic 2Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical
Engineering, Trojanova 13, 120 00 Praha 2, Czech Republic 3Institute of Plasma Physics, The Academy of Sciences of the Czech Republic, Za
Slovankou 1782/3, 182 00 Prague, Czech Republic
We used a free-standing grating spectrometer with 0.01 nm spectral resolution to compare spectral characteristics of two table-top sources of extreme ultraviolet (XUV) radiation -
laser-produced plasma from a gas-puff target and plasma produced by pinching capillary discharge. The spectral line at 2.88 nm emitted by nitrogen plasma was of particular
interest because it can be used for quasi-monochromatic imaging in the XUV water window. The pulse energy produced by the discharge plasma source at 2.88 nm was found to be about one order higher compared to the laser-plasma source (0.16 mJ srad-1 and 0.02 mJ
srad-1, respectively). On the other hand, the radiation from laser-plasma is more spectrally pure as the spectrum of discharge plasma contains additional weak emission lines of carbon
ions generated from the insulating oil.
Presenting Author
Dr. Dalibor Pánek is a Faculty of Biomedical Engineering in the Department
of Natural Sciences, Czech Technical University in Prague.
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Source Brightness Requirements for EUV Microscopes
Larissa Juschkin1, Fergal O’Reilly2
1RWTH Aachen University, Experimental Physics of EUV, Steinbachstr. 15, 52074
Aachen, Germany and JARA - Fundamentals of Future Information Technology (FIT), 52425 Jülich,
Germany 2School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
This paper addresses microscopy with plasma based laboratory extreme ultraviolet (EUV)
and soft-x-ray sources. The focus is set on the determination of the necessary source parameters like radiance and size from fundamental considerations of the achievable
sample resolution, image contrast, detector quantum efficiency and required throughput. Two basic phenomena coming from wave-particle duality of photons are taken into
account: the influence of photon noise on signal detection and conservation of light etendue and radiant flux. Two cases are considered in more detailed – resolution optimized bright field microscopy and sensitivity optimized dark field microscopy. Inspection of EUV masks
and mask blanks required for EUV lithography at 13.5 nm wavelength is chosen as an illustration for both cases.
Presenting Author
Prof. Dr. rer. nat. Larissa Juschkin received her diploma degree in plasma
physics (1995) from the Novosibirsk State University, Russia and Ph.D.
(2001) from the Ruhr-University Bochum, Germany. She worked as the
R&D head at AIXUV GmbH, Germany (2001 – 2005) on the development of
EUV sources and systems for metrology. From 2006 to 2010 she was the
EUV Technology group leader at the RWTH Aachen University, Chair for
Technology of Optical Systems (RWTH-TOS). In 2011 she joined the Plasma
Spectroscopy Group at the University College Dublin and was working on
the investigation of short wavelength radiation from laser produced
plasmas with an emphasis on atomic processes in highly ionized ions. In
2012 she was called to a professorship for Experimental Physics of Extreme
Ultraviolet at the RWTH Aachen University. Her scientific interests and
activities are concentrated on plasma based short-wavelength radiation
sources and their applications, spectroscopy of highly ionized plasmas, EUV
metrology and systems, surface and thin film characterization by
spectroscopic reflectometry, EUV microscopy and lithography.
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R&D Actinic Blank Inspection Microscope
Larissa Juschkin1, Stefan Herbert2, Aleksey Maryasov2, Serhiy Danylyuk2, Rainer
Lebert3
1RWTH Aachen University, Experimental Physics of EUV, Steinbachstr. 15, 52074 Aachen, Germany
2RWTH Aachen University, Chair for Technology of Optical Systems, 52074 Aachen, Germany
3Bruker Advanced Supercon GmbH, Waltherstrasse 49-51, 51069 Köln, Germany
One of the most challenging requirements for the next generation EUV lithography at 13.5
nm or even 6.X nm is an extremely low amount of critically sized defects on mask and mask blanks for mass chip production. Fast and reliable defect inspection of such mask
blanks is still an open keystone of EUV-technology. We have intensively studied this task experimentally and theoretically within our own feasibility research. We summarize the
status of our work as • Experimental results obtained with the actinic Schwarzschild objective based
microscope operating with an EUV-LAMP discharge source from Bruker Advanced Supercon.
• Parameter studies on defect size sensitivity of actinic inspection in dark field mode without resolving the defects.
• Theoretical studies on defect mapping algorithm, tool sensitivity limits and defect detection probability calculations.
We present the concept and the implementation status of the stand-alone R&D ABIT
demonstrator.
Funding by the German minster for Science and Education (BMBF) within the project “13 N10572: “EUV mask” in the consortium “EUV Lithographie für den 22 nm Knoten” is appreciated.
Presenting Author
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Exploring the Resolution Limit of the Talbot lithography with EUV Light
Hyun-su Kim1, Serhiy Danylyuk2, Sascha Brose2, Klaus Bergmann3, Detlev Grützmacher4, Larissa Juschkin1
1RWTH Aachen University, Experimental Physics of EUV, Steinbachstr. 15, 52074
Aachen, Germany 2RWTH Aachen University, Chair for Technology of Optical Systems, 52074 Aachen,
Germany 3Fraunhofer Institute for Laser Technology, Steinbachstr. 15, Aachen, Germany 4Peter Grünberg Institute 9 (PGI-9): Semiconductor Nanoelectronics, Research
Center Jülich
and JARA - Fundamentals of Future Information Technology (FIT), 52425 Jülich,
Germany
Lithography has been in a challenge to bring the resolution down to 10 nm level. Self-imaging Talbot lithography is a promising candidate for the high resolution printing.
Utilizing EUV radiation with wavelengths around 11 nm increases the achievable resolution due to the much shorter wavelength in comparison to the conventional UV radiation. However as the size of structures on the mask approaches the wavelength of the radiation,
diffraction influence needs to be evaluated precisely to estimate the achievable resolution and quality of the patterns.
Here we present the results of FDTD simulation of the diffraction on EUV transmission masks in dependence on period (pitch) of the mask, with the aim to determine the
resolution that can be realistically achieved with the EUV Talbot lithography. Additionally, latest experimental achievements of laboratory-based EUV Talbot lithography will be
reported and compared with the results of the numerical simulations.
Presenting Author
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S42
XUV Spectroscopy of the Interaction of Laser-produced Plasma with Solid Surfaces
A S Kuznetsov1, R Stuik2, F Bijkerk1,3, and A P Shevelko4.
1 FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Postbus
1207, 3430 BE Nieuwegein, The Netherlands (www.differ.nl) 2 Leiden Observatory, Universiteit Leiden, Postbus 9513,2300 RA Leiden, The
Netherlands 3 MESA+ Institute for Nanotechnology, University of Twente, Postbus 217, 7500 AE
Enschede, The Netherlands 4 P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 117924
Moscow, Russia
Processes of interaction of dense, laser produced plasma (LPP) with solid surfaces represent an effective tool for controlled studies of various aspects of plasma-wall interaction, for
instance simulating transient events in fusion reactors or EUV light sources and source exposed materials. A wide range of parameters can be explored by changing laser power, target and/or wall material, or target-wall distances. XUV and VUV radiation emitted during
this interaction allows the usage of well-established in-situ diagnostics (X-ray and XUV spectroscopy) to quantify and control the interaction.
In the current work, intense XUV radiation was observed during interaction of low
temperature LPPs and wall materials [1]. LPPs created on solid targets (CF2 and Al) by a KrF laser were colliding with a solid wall placed on various distances from the target. The spectral and spatial structure of XUV radiation were studied by means of analyzing XUV
spectra of F and Al ions.. At large plasma-wall distances three body recombination was identified as the dominating process responsible for ionic level population and radiation.
The experiments demonstrated an effective way to create low temperature (Te~1-10 eV) plasmas interacting with the solid surfaces and to study the root causes of materials damage.
[1] Kuznetsov A S et al Plasma Phys. Control Fusion 54 (2012) 085019
Presenting Author
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High-brightness Liquid-jet Laser-plasma Enabling 10-second-exposure Water-window Cryo Microscopy
M. Selin1, D. H. Martz1, O. von Hofsten1, E. Fogelquist1, A. Holmberg1, U.
Vogt1, H. Legall2, G. Blobel2, C. Seim3, H.Stiel2, and H. M. Hertz1
1Biomedical and X-Ray Physics, Dept. of Applied Physics, KTH Royal Inst. of
Technology/Albanova, 10691 Stockholm, Sweden 2Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany
3Institute of Optics and Atomic Physics - Analytical X-ray physics, Technische
Universität Berlin, 10623 Berlin, Germany
During the last few decades the average and peak spectral brightness of large-scale
accelerator-based x-ray sources has increased rapidly, enabling a wealth of novel x-ray methods. In contrast, the brightness of table-top sources has developed slower, limiting
the spread of synchrotron-based techniques such as, e.g., water-window x-ray microscopy to a wider scientific community. The soft x-ray source in Stockholm is based on a liquid-nitrogen-jet as regenerative target material, which is excited to a plasma by a high-power
pulsed laser. The Kα emission line of the 20 μm plasma produce a narrow-band line at 2.48 nm in the emitted spectrum, where we have achieved a brightness of >1×1012
ph/(s×sr×μm2×line). To our knowledge this makes it the highest average brightness table-top water-window source. We combine the source with our x-ray microscope and demonstrate high-resolution water-window imaging of cryo-frozen cells with 10-second-
range exposure times, comparable to the early synchrotron-based microscopes.
Presenting Author
Mårten Selin got his M.Sc. in Applied Physics at KTH - Royal Institute of
Technology in Sweden. He is now a PhD-student in the Biomedical and X-
ray Physics group at KTH. His thesis is focused on X-ray optics and X-ray
generation with a special emphasis on X-ray microscopy. Currently he is
responsible for and taking images of cryo frozen bio-samples with the
Stockholm Soft X-ray Microscope.
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S44
Research of the CO2 Laser MOPA System
Wang Xinbing1*, Zuo DuLuo1, Lu Peixiang2
1Wuhan National Laboratory for Optoelectronics, Huazhong University of Science
and Technology, Wuhan 430074, China 2 School of Physics, Huazhong University of Science and Technology, Wuhan
430074, China
Experimental research of a pulse CO2 laser MOPA system was presented in this report. The
laser amplifier is consisted of two CP4000 fast axial flow CO2 lasers which can produce 4 kW CW laser output each. A mechanical Q-switched CO2 laser oscillator with a pulse repetition rate of 1-12 kHz and an AO Q-switched low pressure DC discharged wavelength
tunable CO2 laser oscillator with a pulse repetition of 10-70 kHz were made, the pulse duration for both oscillator is about 200 ns. The maximum average power of 1 kW (with
nearly TEM00 beam quality) can be obtain in our CO2 laser MOPA system, while the pulse duration did not change after the amplifier, and the self-oscillation of the MOPA system was not observed. In the future the laser pulse duration will be shortened by the combination of
cavity dumping and electro-optical Q-switching.
Presenting Author
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Corrosion-resistant, Triple-wavelength Mg/SiC Multilayer Coatings for the 25-80 nm Wavelength Region
Regina Soufli1, Mónica Fernández-Perea1, Jeff C. Robinson1, Sherry L. Baker1, Jennifer Alameda1, Christopher C. Walton1, Luis Rodríguez-De Marcos2, Jose A.
Méndez2, Juan I. Larruquert2, Eric M. Gullikson3
1Lawrence Livermore National Laboratory, Livermore, California, US 2Instituto de Óptica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
3Lawrence Berkeley National Laboratory, Berkeley, California, US
Mg/SiC could be the best reflective multilayer coating in the 25-80 nm wavelength region
for applications such as solar physics and tabletop extreme ultraviolet laser sources which are used for plasma studies, materials characterization, photochemistry, nanopatterning,
and ultrafast single-shot microscopy. Mg/SiC possesses a unique combination of favorable reflective properties, unmatched by any other candidate multilayer coating in the 25-80 nm region: consistently high reflectance, near-zero film stress, good spectral selectivity and
thermal stability up to 350 C. However, Mg/SiC suffers from Mg-related corrosion, an insidious problem which completely degrades reflectance and has prevented Mg/SiC from
being used in applications that require long lifetime stability. We have elucidated the origins and mechanisms of corrosion propagation within Mg/SiC multilayers. Based on our findings, we have demonstrated an efficient and simple-to-implement corrosion barrier for Mg/SiC
multilayers. The barrier consists of nanometer-scale Mg and Al layers that intermix spontaneously to form a partially amorphous Al-Mg layer and is shown to dramatically
reduce atmospheric corrosion while maintaining the unique combination of favorable Mg/SiC reflective properties. We have demonstrated experimentally different concepts for
corrosion-resistant Mg/SiC multilayers which achieve high reflectance in up to three narrow bands simultaneously, in the 25-80 nm region. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
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Presenting Author
Regina Soufli received her Ph.D. in Electrical Engineering from the
University of California, Berkeley, and was staff scientist at the Harvard-
Smithsonian Center for Astrophysics working for NASA’s Chandra X-ray
Observatory. At Lawrence Livermore National Lab she has been principal
investigator on EUV/x-ray optics programs for EUV lithography, solar
physics, synchrotron and free-electron lasers, and high-energy physics.
She has recently been working on x-ray optics for the Linac Coherent Light
Source (LCLS), the world's first x-ray free electron laser, and on EUV
multilayer optics for NASA/NOAA's space weather satellites and NASA's
Solar Dynamics Observatory. Her interests are in EUV/x-ray interactions
with matter, surface science, thin films, roughness and scattering. She is
author of over 60 publications and a book chapter, and has received two
“R&D 100” awards.
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S46
XUV and EUV Applications with EUV Sources for Metrology
Rainer Lebert, Thomas Mißalla, Azadeh Farahzadi, Christoph Phiesel, Urs Wiesemann, and Wolfgang Diete
Bruker Advanced Supercon GmbH, Waltherstrasse 49-51, 51069 Köln-Dellbrück,
Germany
EUV sources for metrology are a keystone for the infrastructure of EUVL. Within Bruker ASC and with our research partners we are investigating and producing discharge and laser produced sources since 1996, such that we can provide and engineer matched solutions for
many tasks.
With the discharge based EUV-source for metrology – our EUV-Lamp – first shipped in 2001 we meanwhile have produced about 20 systems. The typical EUV-Lamp delivers up to 750
mW/(2 sr) of in-band EUV (> 8 W/(2 sr) of total EUV). About 500 M pulses of electrode
life supports up to one year of 8 hour per day emission. At our partner Fraunhofer Institute for Lasertechnics, prototype sources based on similar platform are delivering up to 40 W/(2
sr) of in-band EUV; with brightness of up > 20 W/mm²/sr. When source brightness is the
issue, laser produced (LPP) sources are advantageous. Members of our group are working since 1997 on and with LPP EUV sources.
Most of the EUV-Lamps, which we have produced are specially interfaced or directly integrated into tool solutions. The lamps have been and are being used in EUV-
Reflectometers, EUV resist exposures, EUV and x-ray microscopes, EUV-scatterometer, EUV- Interference Lithography, in source metrology calibration, for optics qualification and
as sources for spectrograph calibration in fusion and solar physics. LPP sources are used in our spectrophotometer (CEUVS) and in x-ray microscopes. Research and use of EUV-LPP sources is ongoing at our research partners at RAC, Remagen, LZH, Hannover, MBI Berlin
and FhG-ILT, Aachen.
Based on these sources and with our proprietary polychromatic reflectometry, we have realized tools, which fulfill such high demands together with fast measurement times. Typically, for characterization of one small spot on a sample of << 0.1 mm² in size,
exposure times – depending on spectral resolution - of 5 – 20 seconds are sufficient, which allow to characterize > 180 spots per hour or > 3 samples per hour with > 30 spots on
each sample. This has been demonstrated at our actinic EUV mask and mask blank reflectometer (EUV-MBR) and in flexible EUV characterization of normal and grazing incidence and foil and gas transmission with our new EUV-Spectrophotometer CEUVS.
With tailoring source features, solutions like actinic defect inspection (EUV-ABIT), EUV
interference lithography and critical dimension scatterometry, optics scatterometry and research in fusion and solar physics have been demonstrated.
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Support by the German minster for Science and Education (BMBF) within the project “13 N10572: “EUV mask” in the consortium “EUV Lithographie für den 22nm Knoten” is appreciated.Some of the work is from collaborations with RWTH Aachen, RAC Remagen, Fraunhofer Institute for Lasertechnics, Aachen and MBI Berlin.
Presenting Author
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Next Generation of EUV Lithography: Challenges and Opportunities
Andrei M. Yakunin, Vadim Banine
ASML, Veldhoven, The Netherlands
Reduction of light wavelength used in Litho tools has enabled shrink of printed feature.
Current immersion systems based on 193 nm are printing features as small as 32 nm. State of the art EUV lithography has already demonstrated excellent capability to print 18
nm features in single exposure and is expected to enable printing of <16 nm features.
Shrinking wavelength with maintaining or increasing throughput is a traditional way to
enable improved imaging for the last 20 years. Transition from 13.5 nm to a shorter wavelength offers a possibility to combine high imaging capabilities with still managing
process window. Change of working wavelength will introduce changes to a number of subsystems of the lithographer including source and optics.
Our work is aiming at investigation of the potential of a number of shorter wavelength candidates λ<13.5 nm. Here we review requirements that these systems should meet to
enable continuation of lithography roadmap below 7 nm. Specifications of the key system elements including source, optics, resist are discussed.
Presenting Author
Dr. Andrei M. Yakunin is currently project leader at ASML Research. He has
worked for ASML since 2007 with the primary focus on EUV sources. He
obtained his master degree in applied physics and mathematics from
Moscow Institute of Physics and Technology in 2001. He received his PhD
Cum Laude in 2005 from Eindhoven University of Technology, The
Netherlands (TU/e). The subject of his PhD work was the study of magnetic
impurities in III-V semiconductors at nano-scale. From 2005-2007 he did
his postdoctoral work at TU/e in the field of semiconductor spectroscopy
and single photon emission. He has over 15 publications and over 20
patens. He is also the winner of ASML patent award.
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S48
Erasmus Mundus Joint Doctorate Programme EXTATIC (EUV and X-Ray Training in Advanced Technologies for Interdisciplinary
Cooperation) - Program Review
Paul van Kampen
School of Physical Sciences, Dublin City University, Dublin, Ireland
The Erasmus Mundus Joint Doctorate programme EXTATIC (EUV and X-Ray Training in
Advanced Technologies for Interdisciplinary Cooperation) offers a postgraduate education program in extreme ultraviolet (EUV) and X-ray science to a new generation of high achieving graduate students. It provides the transferable skills necessary for thriving
careers in a growing domain that underpins innovative technological development across a diverse range of disciplines in the ‘nanotechnology waveband’ such as EUV Lithography and
X-ray microscopy in the ‘water window’. EXTATIC provides a combination of ‘hands-on’ research training, industrial placements, courses and workshops on scientific and complementary transferable skills. This talk is an overview of the EXTATIC program and
the projects that have just commenced under the 2012 edition.
Presenting Author
Paul van Kampen is a Senior Lecturer at the School of Physical Sciences at
Dublin City University, and a member of the Centre for the Advancement of
Science and Mathematics Teaching and Learning (CASTeL) and the National
Centre for Plasma Science and Technology (NCPST). He obtained a Ph.D. in
Experimental Physics (EUV Photoabsorption in Atoms and Ions) from
University College Dublin. Paul teaches physics and physics education at
undergraduate and postgraduate level, and is heavily involved in science
teacher education. He has been Academic Director of the EXTATIC EMJD
program since September 2011. Paul is married to Lorraine with two
daughters, Maria and Amy.
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S49
EUVL - A Reality in the Making The Reality of Laser Assisted Discharge Plasma EUV Light
Sources
Jeroen Jonkers
XTREME technologies, GmbH, Steinbachstrasse 15, 52074 Aachen, Germany
Scalable in power and delivering highly repeatable and stable output at 13.5 nm, XTREME technologies GmbH’s Laser produced Discharge Plasma (LDP) technology is maturing fast and now proven a viable solution to generate the EUV photons that will power next
generation lithography EUV exposure tool.
After demonstrating experimentally the long term scalability of LDP, the most recent performance of integrated sources in the Lab and in the Fab will be discussed. The
challenges and improvements in the demonstrated usable output will be detailed. However, because high throughput without stability would be tantamount to printing defective semiconductor devices merely at high speed, to increase EUV power without
compromising dose stability is critical. LDP dose stability technology will be outlined and performance data provided.
Alongside, the success of EUV in an HVM environment will require high availability and reliability. The status of current LDP sources operated 7x24 will be reported. Highlighting
the development status of the different modules, the current technological path of LDP towards HVM will then be summarized.
Presenting Author
Jeroen Jonkers received his PhD in Plasma Physics at the Eindhoven
University of Technology (Eindhoven, The Netherlands) in 1998. He then
joined Philips Research in Eindhoven, The Netherlands. From 2001 to 2009,
Dr. Jonkers worked at Philips Extreme EUV GmbH as Senior Scientist and
Program Manager. He is currently Product Architect at Xtreme technologies
GmbH.
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S50
Multilayers for 6.8 nm Wavelength
I.A. Makhotkin1, E. Louis1 ,E. Zoethout1, R.W.E. van de Kruijs1, Andrei M. Yakunin2, Stephan Müllender3 and F. Bijkerk1,4
1 FOM Institute DIFFER - Dutch Institute for Fundamental Energy Research,
Nieuwegein, the Netherlands 2 ASML, Veldhoven, the Netherlands
3 Carl Zeiss SMT GmbH, Oberkochen, Germany 4 MESA+ Institute for Nanotechnology, University of Twente, Enschede, the
Netherlands
Lithography based on the wavelength of 6.x nm is considered to be a potential extension of the current 13.5 nm EUV lithography. Light sources might be based on Tb or Gd. The
published spectra of plasmas created from these materials show highest intensities at 6.5 and 6.8 nm respectively. Multilayer mirrors (MLMs) based on La and B show the highest optical contrast for the 6.6-7 nm wavelength range and a maximum reflectance at 6.64
nm, where the B absorption is minimal. It is not possible to design high reflective B-based mirrors for 6.5 nm because this would be below the B-K absorption edge. In theory the
reflectivity of La/B MLMs at 6.8 nm is only a few percent lower than at the optimal wavelength of 6.64 nm, but measurements of real multilayer mirrors show a significantly larger reduction of reflectivity at 6.8 nm. The origin of this larger drop is the reduced
optical contrast of the deposited La/B mirror with respect to theoretical case. In the presentation we will discuss how the multilayer structure influences its reflectivity profile
and the ways to optimize La/B mirrors for 6.8 nm.
Presenting Author
Eric Louis is a senior scientist at FOM Rijnhuizen (the Netherlands) where
he is involved in research and development of soft X-ray and EUV
multilayer reflective coatings since 1992. He worked on multilayers for
several applications such as space research and synchrotron beam lines,
but focused his research primarily on multilayers for EUV lithography. As
leader of the group ‘Advanced applications of XUV Optics’, Eric Louis has
been responsible for research, development and coating of various optics
for EUV lithography.
The extensive know how developed for this application is the basis for the
development of multilayer coated optics for XUV and soft X-ray free
electron lasers.
2012 International Workshop on EUV and Soft X-Ray Sources
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S51
EUV Source For Metrology of EUV Masks (Tentative title)
Heiko Feldmann
Carl Zeiss, 73447 Oberkochen, Germany
The introduction of EUV lithography with its huge jump in wavelength and resolution is extremely attractive for semiconductor manufacturing. Large investments from key players
of the industry are now taking place in order to move EUV to the chip fab. EUV sources are a key element for this new infrastructure, not only for lithography itself but also for
metrology and qualification of all components participating in EUV imaging.
The talk focuses on sources for metrology of lithographic masks. Mask metrology tools supporting mass production of semiconductors need to have high throughput, high
precision and high reliability. All this has direct influence on the light sources that can be employed. For defect review, where the need for actinic optics is most obvious within the mask industry, a first generation of AIMS(TM) EUV systems is now being built. With the
further development of EUV, requirements on AIMS will increase, and this leads to more challenging demands for its light source.
Presenting Author
Heiko Feldmann works as Principal Scientist for Carl Zeiss SMT GmbH.
After graduating with a PhD in Theoretical Physics from Würzburg
University. He first started as an optical designer with Carl Zeiss. His
focus now is on system concepts and technology roadmap. One of his
recent projects was the concept layout of the metrology core of
AIMS(TM) EUV.
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S52
Modeling and Optimization of Pre-conditioned LPP targets
K. N. Koshelev1,2, V. V. Ivanov1,2, V. G. Novikov1,3, V. M. Krivtsun1,2, A. S. Grushin1,3 , V. Medvedev4
1RnD-ISAN, Troitsk, 142090 Russia
2Institute of Spectroscopy RAS, Troitsk, 142090 Russia 3Keldysh Institute of Applied Mathematics RAS, Moscow, 125047 Russia
4Dutch Institute for Fundamental Energy Research, Nieuwegein, The Netherlands
An integrated model is developed to describe the hydrodynamics, atomic, and radiation processes that take place in EUV sources based on laser-produced plasma with an
advanced tin targets. The modeling was performed by using the RZLINE code — a numerical code for the simulation of EUV emission by hot dense plasmas. The purpose of the simulation is to evaluate the spectral characteristics of the radiation source, conversion
efficiency, source size, evaporation rate of the target, energetic, and space distribution of debris (nanoparticles, neutrals, and ions). The optimization of different type of targets is
fulfilled.
Presenting Author
Konstantin N. Koshelev is the president of RnD-ISAN and a leading
scientific specialist in plasma physics and atomic spectroscopy. He was
invited professor at Pierre and Marie Curie University (1991), Orsay
University (1992) and Auburn University (1990 and 1995).
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S53
Modeling of Absorption and Scattering of IR laser Radiation by LPP Targets
A. S. Grushin1,2, I. P. Tsygvintsev1,2, V. G. Novikov1,2, V. V. Ivanov1,3
1RnD-ISAN, Troitsk, 142090 Russia 2Keldysh Institute of Applied Mathematics RAS, Moscow, 125047 Russia
3Institute for Spectroscopy RAS, Troitsk, 142090 Russia
A mathematical model and algorithm for simulation of laser radiation absorption with
accounting refraction and reflection by target plasma in the geometrical optics approximation is presented. An analytical solution of the differential equations assuming a
constant gradient of the square of optical coefficient in the cell is proposed. A numerical calculation algorithm is developed, and estimation of its convergence has been done. For a partial accounting of effects that are beyond the geometrical optics approximation, one-
dimensional model of the layered medium was used.
Presenting Author
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S54
Modeling of Plasma Dynamics and EUV Generation for Distributed Sn Targets Irradiated with Short Laser Pulses
V. Ivanov1, A. Grushin2, V. Novikov2, V. Medvedev3, V. Krivtsun1, A. Yakunin4, and
K. Koshelev1
1Institute for Spectroscopy RAS, Troitsk, Russia
2Keldysh Institute of Applied Mathematics, Moscow, Russia 3Dutch Institute for Fundamental Energy Research, Nieuwegein, The Netherlands
4ASML, The Netherlands
Generation efficiency of EUV radiation by laser-produced plasma (LPP) sources is defined by
the effective coupling of the laser radiation to Sn target. Expected that usage of the distributed targets (DT) consisting of a number of small (from one to few micrometers) droplets distributed over the volume with a total size of a few hundred micrometers allows
noticeably increase laser radiation absorption and in-band conversion efficiency.
To simulate optical, atomic and hydrodynamic processes in LPP sources based on DT approach, an integrated model is being developed. The hydrodynamic plasma model includes diffusion-like radiation transport with 100 and more groups of spectral groups with
well represented in-band EUV. Non-stationary ionization (recombination) processes are also included. Energy fluxes to and from a target surface are taken into account: electron and
ion thermo-conductivity, radiative transfer in every spectral group, condensation and recombination of vapor and plasma. Verified atomic data are used for calculation opacity
and emissivity. Results of a numerical simulation are presented for various types of DT.
Presenting Author
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S55
Optics for EUV/XUV/XR Sources and Laboratory Submicron Microscopy
Ladislav Pina1, Veronika Pickova1, Radka Havlikova1, Hana Zakova2, Alexandr Jancarek1, Adolf Inneman3, Martin Horvath3, Jiri Marsik3, Peter Oberta3, Henryk
Fiedorowicz4, Andrzej Bartnik4
1 Czech Technical University in Prague, Faculty of Nuclear Sciences and Phys. Engineering, 115 19 Prague 1, Czech Republic
2Czech Technical University in Prague, Faculty of Biomedical Engineering, 272 01 Kladno, Czech Republic
3Rigaku Innovative Technologies Europe, 142 21 Prague 4, Czech Republic 4Military University of Technology, Institute of Optoelectronics, 00-908 Warszawa
49, Poland
Presenting Author
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S56
Unresolved Transition Arrays and their role in EUV and Soft X-ray Source Development
Gerry O’Sullivan1, John Costello2, Thomas Cummins1, Rebekah D’Arcy1, Padraig Dunne1, Akira Endo3, Paddy Hayden2, Takeshi Higashiguchi4, Imam Kambali1,
Deirdre Kilbane1, Bowen Li1, Colm O’Gorman1, Takamitsu Otsuka4, Emma Sokell1 and Noboru Yugami4
1School of Physics, University College Dublin, Belfield, Dublin 4, Ireland. 2School of Physics, Dublin City University, Glasnevin, Dublin 9
3HiLASE Project, Institute of Physics AS, CR, Na Slovance 2, 18221 Prague 8, Czech
Republic 4Department of Advanced Interdisciplinary Sciences, Utsunomiya University, Yoto 7-
1-2, Utsunomiya, Tochigi 321-8585 Japan.
Unresolved transition arrays (UTA) appear frequently in the extreme ultraviolet (EUV) and and soft x-ray spectra of medium and high Z-elements. They broadly fall into two types, Δn = 0 arrays, where emission from adjacent ion stages overlap in energy and whose
intensity is very sensitive to plasma ion density and Δn = 1 transitions where emission moves to shorter wavelengths in successive ion stages thereby reducing the radiation
transport problem. Because of their inherent brightness the former are used or have been proposed as sources for EUV lithography or as broad-band water window sources. Δn = 0 arrays are broad at intermediate Z values (such as Sn, Z=50) decrease in width because of
configuration interaction and orbital contraction effects up to Z= 60 or so and thereafter broaden again reflecting the effects of spin orbit splitting on the configurations involved.
Because of their Z scaling, use at shorter wavelengths requires higher temperature plasmas and recent work has shown that Δn = 1 arrays may provide useful sources at shorter wavelength at lower electron temperatures, especially if used with mirrors of limited
reflection bandwidth. We have also found that dielectronic recombination and satellite emission can also enhance the emission in these arrays.
2012 International Workshop on EUV and Soft X-Ray Sources
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Presenting Author
Prof. Gerry O’Sullivan obtained his PhD from University College Dublin
(UCD) in 1980 for work on the spectroscopy of laser produced plasmas of
medium to high Z elements that included the first observation the
unresolved arrays now studied as emission sources for EUVL at 13.5 and
6.x nm, changes in their EUV emission due to opacity and the application of
higher Z plasmas as sources of EUV continuum radiation. After a brief
period at the University of Maryland and National Bureau of Standards he
returned to Dublin where he was employed at Dublin City University from
1981 before moving to a lectureship at UCD in 1986. He is currently a
Professor at UCD and served as Head of the School of Physics from 2002 -
2008. His research interests include EUV and soft x-ray continuum
generation from laser produced plasmas and application to inner shell
photoabsorption studies of atoms, ions and molecules, investigation of
unresolved transition arrays (UTA) and their application as high brightness
EUV sources, determination of the electronic structure of medium and high
Z ions and spatial and temporal characterisation of laser produced plasmas.
In recent years, aided primarily by funding from Science Foundation
Ireland, this work has focussed strongly on studies relevant to the
development of EUVL sources. He has published more than 110 papers and
is a member of the editorial board of European Journal of Physics. He is a
member of the Royal Irish Academy and a Fellow of the Institute of Physics.
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S57
New High Reflective Multilayer Designs for the EUV and Soft X-ray Range
Marco Perske, Hagen Pauer, Tobias Fiedler, Sergiy Yulin, Viatcheslav Nesterenko, Mark Schürmann, Torsten Feigl, Norbert Kaiser
Fraunhofer-Institut für Angewandte Optik und Feinmechanik, Albert-Einstein-Str. 7, 07745 Jena,
Germany
EUV Lithography is the most promising method enabling semiconductor scaling to resolutions of 22 nm and below. Due to the absorption in the EUV spectral range, EUV optics such as collector, illumination and projection optics, have to be coated with a highly
reflective multilayer coating in order to achieve the required peak reflectance of close to 70 %.
But the more EUV Lithography is pushed to high volume manufacturing, the higher is also
the demand on optics for very special measurement application in these wavelengths. The Fraunhofer IOF possesses extensive knowledge of the optical, mechanical and chemical
properties of substrate and layer materials as well as corresponding design software and coating machines.
This paper provides a review of individually designed, refined and optimized multilayer coatings for broadband mirrors, beam splitters and polarizers in the EUV and soft X-ray
range. Latest coating results will be presented.
Presenting Author
Marco Perske received a Dipl.-Ing. degree in 2006 and M.Eng. degree in
2009 both at the University of Applied Science Jena. Since 2007 he works
at the Fraunhofer – Institute for Applied Optics and Precision Engineering as
scientist and process engineer with main focus on EUV and X-ray optics.
2012 International Workshop on EUV and Soft X-Ray Sources
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S58
Discharge based EUV Source for Metrology
Klaus Bergmann
Fraunhofer Institute for Laser Technology, Steinbachstr. 15, D-52074 Aachen,
Germany
The current status and the scaling potential for the brilliance of the Hollow Cathode
triggered pinch plasma (HCT) are presented. Such sources are already in commercial use for the technology development of EUV lithography, e.g., for mirror contamination studies, mask blank inspection or resist development. For future Aerial Imaging Microscopy (AIMS)
of EUV masks special care has to be devoted to the brilliance scaling in order to guarantee a sufficient throughput. With the recent state of development already more than 20
W/(mm2 sr 2% b.w.) at a central wavelength of 13.5 nm could be demonstrated. This is close to the specification for a future AIMS tool. Based on experimental data, the roadmap for achieving more than 35 W/(mm2 sr) and the maximum achievable brilliance for the
concept under consideration will be discussed.
Presenting Author
Klaus Bergmann received his PhD degree from the Faculty for Engineering,
RWTH Aachen University, in 1996 in the field of discharge based soft x-ray
sources. Since 1992, he has been with the Department for Plasma
Technology at the Fraunhofer Institute for Laser Technology. Currently, he
is Group Leader for the development of radiation sources for semiconductor
lithography.
2012 International Workshop on EUV and Soft X-Ray Sources
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S59
Nanoscale Multilayer Membranes as Optical Elements for EUVL
Nikolay Chkhalo, Mikhail Drozdov, Evgeny Kluenkov, Aleksei Lopatin,
Valerii Luchin, Nikolay Salashchenko, Nikolay Tsybin*) Leonid Sjmaenok**)
Vadim Banine, Luigi Scaccabarozzi, Andrei Yakunin***)
*) Institute for Physics of Microstructures RAS,Ulyanova 46, 603155 Nizhniy Novgorod, Russia
**) PhysTeX, Jos Francotteweg 6b, 6291 GP Vaals, Netherlands ***) ASML Netherlands, De Run 6501, 5504 DR Veldhoven, Netherlands
Transparent optical elements for EUV could have several critical applications, ranging from spectral filters to particle protection (e.g., pellicle for reticles). Since practically no
material is transparent to EUV, the only known solution is to make the optical element extremely thin (<100nm). This results in enormous challenges in manufacturing (e.g.,
making the membrane free-standing) and in meeting the requirements on heat load, mechanical strength, EUV transmission, etc.
In this paper we present recent developments on free-standing multilayer membranes, fabricated and studied as EUV transparent elements for lithography tools.
Membranes 53 ÷ 40 nm-thick, and as large as 160mm, have been fabricated. They provide inband transmission up to 74-76% and are considered as potential spectral purity filters
2÷103. SPF membranes
were tested to withstand prolonged heating at 950°C and repetitive deformations under modulated power load.
Stopping fast debris particles as valuable additional functionality of SPF membranes has been studied with an LPP source and a particle velocity filter. It was found that membranes
are not punched through by metal particles with sub-micron dimensions and velocities up to 1000 m/s. Development of super-thin membranes as pellicles, targeting a two-pass
inband transmission above 80% is in progress. Currently a one-pass transmission of 86% has been demonstrated with 25 nm membranes on 80 mm aperture frames. The samples sustained absorbed power loads above 1 W/cm2 with < 0.1 mm deviations from the initial
quasi-stretched surface shape and in-plane acceleration of at least 15g. Achievement of higher inband transmission along with solving specific application issues is planned for this
year.
Presenting Author
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S60
EUV Spectra of Highly Charged Heavy Ions in the NIST EBIT
D. Kilbanea, J. D. Gillaspyb, Yu. Ralchenkob, J. Readerb, G. O'Sullivana
a School of Physics, University College Dublin, Belfield, Dublin 4, Ireland b National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Measurements of extreme ultraviolet (EUV) radiation from highly-charged heavy ions were
made at the National Institute of Standards and Technology (NIST). The ions were generated and confined in an electron beam ion trap (EBIT) and the spectra were recorded with a flat-field grazing-incidence spectrometer in the wavelength range 3-17 nm. The EBIT
was operated at beam energies that optimized the production of Rb-like to Cu-like Gd ions. Strong (N-shell) n=4 – n=4 transitions were identified with the collisional-radiative (CR)
modeling code NOMAD [1]. EUV spectra of Gd, Dy and W are dominated by the presence of narrow unresolved transition arrays (UTAs) [2].
These arise from interactions between 4p64dN-14f and 4p54dN+1 configurations and overlap in adjacent ion stages. This work enhances other studies of n=4 to n=4 EUV transitions
carried out at NIST on tungsten [3], hafnium, tantalum and gold [4] and can be used for diagnostics of hot plasmas in fusion devices and for studies of trends in atomic structure. The gadolinium data will aid recent research efforts on next-generation lithographic sources
at shorter wavelengths [5]. [1] Yu. V. Ralchenko, Y. Maron, J. Quant. Spectrosc. Radiat. Transfer 71 609 (2001) [2] C. Bauche-Arnoult, J. Bauche, M. Klapisch, Phys. Rev. A 20 2424 (1979) [3] Yu. Ralchenko, J. Reader, J. M. Pomeroy, J. N. Tan, J. D. Gillaspy, J. Phys. B: At. Mol. Opt. Phys. 40 3861 (2007) [4] I. N. Draganić, Yu. Ralchenko, J. Reader, J. D. Gillaspy, J. N. Tan, J. M. Pomeroy, S. M. Brewer, D. Osin, J. Phys. B: At. Mol. Opt. Phys. 44, 025001 (2011) [5] S. S. Churilov, R. R. Kilidiyarova, A. N. Ryabtsev, S. V. Sadovsky, Phys. Scr. 80, 045303 (2009)
Presenting Author
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S61
New Type of DPP Source with Liquid Tin Jets Electrode - Recent Progress
V.Krivtsun *, O.Yakushev *, A.Vinohodov*, ** , V.Borisov** , V.Ivanov* and
K.Koshelev*.
* RnD-ISAN / EUVLabs, ** TRINITI
A new approach for discharge-produced plasma (DPP) extreme ultraviolet (EUV) sources
based on the usage of two liquid Sn jets as discharge electrodes has been developed and is tested.[1] Discharge was ignited using Nd-YAG laser ablation of one (or both) of jets.
Spectral, time and energy characteristics of EUV radiation are similar to conventional DPP schemes with rotating wheels. Modeling and experiments demonstrate that due to high velocity of the jets the proposed scheme of EUV source able to dissipate up to 200 kW of
electrical power without overheating the nozzles and tin surface.
New EUV source with projected repetition rate up to 8 kHz and dissipated electrical power up to 32 kW in continuous mode and 40 kW in burst mode has been designed and constructed. The power limitation is imposed by parameters of existing discharge excitation
circuit. The Sn jets with up to 2 mm diameters were circulating in a closed loop by means of centrifugal pump with magnetic coupling. In first experiments with repetition rates 100
Hz conversion “in band” efficiency (CE) more than 2% in 2π sr was shown. It was found that the introduced electrode configuration allows the channeling of essential parts of
debris plasma in directions opposite to the EUV collector. [1] New type of DPP source for EUVL based on liquid tin jet electrodes, K. Koshelev, V. Krivtsun, V. Ivanov, O. Yakushev, A. Chekmarev, V. Koloshnikov, E. Snegirev, V. Medvedev J. Micro/Nanolith. MEMS MOEMS 11(2), 021103 (Apr–Jun 2012)
Presenting Author
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S62
Tin LPP Source Modeling for EUVL at 13.5 nm
John White, Padraig Dunne, and Gerry O’Sullivan
University College Dublin, Dublin, Ireland
An unresolved transition array (UTA) can be the strongest feature in EUV LPP spectra,
consisting of thousands of transitions between bands of near-degenerate energy levels [1]. The complexity of the configurations is such that a line-by-line analysis is computationally extremely intensive and statistical methods can be used to characterise a UTA by position
(1) and width (). To estimate emission in a 2% bandwidth centred on 13.5 nm, the weighted oscillator
strength (gf) versus wavelength () is calculated using a Hartree-Fock configuration interaction code [2] for 4d-4f, 4p-4d and 4d-5p transitions. The number of transitions of
some ions exceeds 100,000 lines. Because of the large number of transitions and complexity of the UTA, as well as the
computationally intensive nature of radiation transport calculations, statistical methods can be used to estimate the spectral profile [3]. UTA width can overestimate by a factor of
approximately 2 because of "outliers”. Statistical/convolved LSQ match gives a better fit
(e.g. Sn XI 0.550.20 nm) [4].
Increasing laser power density shows increased in-band UTA brightness [5]. Emission increases and decreases with increased laser intensity (or electron temperature) as the UTA ions move in- and out-of-band, as in the steady-state CR model [6], where an average
temperature and density is assumed over the whole plasma. Wavelength at peak emission also decreases as power density increases as seen in the time-dependant model.
The impact of wavelength and power density on ion distribution and electron
temperature is calculated for a Nd:YAG ( = 1064 and 355 nm) and CO2 ( = 10600 nm)
laser. The laser power densities, , are chosen to keep 2 constant, thus keeping the
electron temperature constant in the CR rate equations [6]. (The 355-nm laser is included to highlight the emission dependence on electron density, primarily three-body
recombination, and gives greatly reduced Sn10+ and Sn11+ ions, the main emitters at 13.5
nm.) The figure of merit shows an increase for the CO2 laser, where the in-band gf is
13.4% greater at 32 eV and 2.7% greater at 36 eV [7].
The influence of reduced electron density in the CO2 LPP ( 1/100, where ne 1/2) is
considered in a 1-D radiation transport model. Plasma opacity is less in the lower electron density CO2 plasma, resulting in less absorption and a brighter source. A more than 2-fold increase in conversion efficiency is predicted for the CO2 laser over that attainable with the
Nd:YAG [7], close to the experimentally observed values [8,9].
2012 International Workshop on EUV and Soft X-Ray Sources
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The 2-D RMHD code Z* [10] models emission in an optically thick tin LPP. The implicit Eulerian-Lagrangian code solves MHD, ionization kinetics with radiation transport and uses
an average atom model to account for all possible states and transitions.
Optimum 4d-4f + 4p-4d in-band emission occurs primarily from the plasma core at an electron temperature of 30-40 eV [11,12]. However the core emission is reduced by self-absorption and absorption in the colder wings because of the high absorption cross section
of lower stage ions [13]. [1] O'Sullivan and Faulkner, Opt. Eng. 33, 3978, 1994. [2] Cowan, The theory of atomic spectra and structure, Berkeley, University of California Press, 1981. [3] Bauche-Arnoult and Bauche, Physica Scripta T40, 58, 1992. [4] J. White, P. Hayden, P. Dunne, A. Cummings, N. Murphy, P. Sheridan, and G. O’Sullivan, J. Appl. Phys. 98, 113301,
2005. [5] P. Hayden, A. Cummings, N. Murphy, G. O’Sullivan, P. Sheridan, J. White, and P. Dunne, J. Appl. Phys. 99, 093302,
2006. [6] Colombant and Tonon, J. Appl. Phys. 44 (8), 3524–3537, 1973. [7] J. White, P. Dunne, P. Hayden, F. O’Reilly, and G. O’Sullivan, Appl. Phys. Lett. 90, 181502, 2007. [8] Y. Tao and M. S. Tillack, Sematech EUV Source Workshop, Vancouver, May, 2006. [9] I. Fomenkov, Sematech EUV Source Workshop, Barcelona, Oct. 2006. [10] S. Zakharov, V.G. Novikov, and P. Choi, EUV Sources for Lithography, editor Vivek Bakshi, Publ., SPIE, 2006. [11] J. White, G. O’Sullivan, S. Zakharov, P. Choi, V. Zakharov, H. Nishimura, S. Fujioka, and K. Nishihara, Appl. Phys. Lett.
92, 151501, 2008.
[12] A. Cummings, G. O’Sullivan, P. Dunne, E. Sokell, N. Murphy, and J. White, J. Phys. D 38, 604, 2005. [13] M. Lysaght, D. Kilbane, N. Murphy, A. Cummings, P. Dunne, and G. O’Sullivan, Phys. Rev. A 72, 014502, 2005.
Presenting Author